PLUMBING 
FIXTURE TRAP; 




An Historical^ Statisticat and Experimental 
EngineeriDg Research on 

ENTED AND UNVENTED TRAPS 




BY 

A. E. HANSEN 

HYDRAUUC AND SANITARY ENGINEER 

2 RECTOR STREET. NEW YORK 



PRICE TWO DOLLARS 




%right]^^.. 



Caffi^IGHT DEPOSITS 



PLUMBING 
FIXTURE TRAPS 



An Historical, Statistical and Experimental 
Engineering Research on 

VENTED AND UNVENTED TRAP5 



? BY 

a/e. HANSEN 

HYDRAULIC AND SANITARY ENGINEER 

2 RECTOR STREET. NEW YORK 



PRICE TWO DOLLARS 



Copyright 1921 by 
A. E. HANSEN 



FEB 131922 









V3" 






PRINTED IN THE UNITED STATES OF AMERICA 
BY HARPER & BROTHERS 



©CI.A654640 



DEDICATION 

To those, who by the skill of their brains 
or their hands, endeavor to uphold the present 
high standards of phimbing design and thus 
aid in the up-building of the health and com- 
fort of the American people, this book is 
respectfully dedicated. 



FOREWORD 

The subject of plumbino- traps is one 
which closely touches every modern 
American home, more intimately perhaps 
than most people realize, These devices are 
intended to intervene securely, permanently, 
and unfailingly between the foulness of the 
sewer on one side and the sweetness of the 
home on the other. Anything, which 
threatens to weaken or destroy this barrier, 
must be shunned and condemned. There is 
no half-way security; absence of complete 
security means danger. 

It is hoped that this book will be used as 
a reference by those whose duty it is to 
prepare or administer plumbing codes, and 
to design, specify, or install plumbing systems. 

The Author 



Plumbing Fixture 

Traps 

AN HISTORICAL, STATISTICAL AND EXPERIMENTAL 
ENGINEERING RESEARCH ON 

VENTED AND UNVENTED TRAPS 




UCH consideration and study has been 
given, much guess work has been at- 
tached to, and many opinions have 
been advanced with regard to the subject of 
non-vented, anti-siphon, non-siphoning or re- 
sealing traps, on their power of resisting 
siphonage and back pressure, and on their 
self-cleansing action, aU as compared with the 
corresponding qualities of the vented bent 
tube or % S traps. 

On this subject a great difference is to be 
noted in the plumbing regulations of the vari- 
ous cities and states; numerous tests have 
been reported; and inventors have found the 
field of anti-siphon traps apparently most 
fruitful. 

It seemed advisable, therefore, to collect 
data of historical, statistical, experimental 
and engineering interest, to combine these 
with the results of experiments made under 
my direction, to draw certain conclusions from 
the entire available information, and to pre- 
sent the same for the information of those in- 
terested in this particular branch of science, 
especially architects, sanitary engineers, plumb- 
ers, and officials of states and municipalities 
having jurisdiction in plumbing work. 

HISTORICAL 

In about 1840 the first plumbing fixtures 
were introduced in Professor Longfellow's 
home in Cambridge, Mass. They included 
water closets and a kitchen sink. The his- 
torian fails to state what attempts were made 
to exclude sewer air, described as "Effluvia," 
from the professor's house. 

In 1856 Charles H. Bush was granted a 
U. S. patent for improvements to the "Bell 
stench trap"; the application states: "The in- 



ventor does not claim as new in themselves, 
the perforated plate or grating, and bell or 
cup with surrounding chamber and central 
exit pipe, arranged as described to form in 
combination a stench trap for sinks, as such 
is old and commonly known as the "Bell 
stench trap." 

This "Bell stench trap" was an ordinary 
bell trap, placed directly against the bottom 
of the kitchen sink underneath its strainer 
outlet. 

In 1860 Alfred Carson, of New York, intro- 
duced an improvement on the Bell trap by 
attaching a miniature septic tank with a hang- 
ing baffle to the underside of a plumbing fix- 
ture. 

W. E. Hatfield, of Newark, appears to de- 
serve the questionable credit of first applying 
in 1862 the principle of a counterweighted 
flap valve, enclosed within a tight box, to the 
waste pipe of a plumbing fixture, which was 
modified in 1868 by F. H. Williams by the 
substitution of a spring operated concave disk. 

In 1872 Thomas Smith, of New York, intro- 
duced a hinged valve trap mechanism designed 
to "check wind blasts from blowing up from 
the sewer." 

During the years 1872 to 1875, the bent pipe 
trap, now designated as the % S or S trap, 
seems to have made its first appearance, but 
who originated its use or adapted it from the 
old English "D" trap is not stated in any of 
the works which I have been able to consult. 
I find, however, that 1875 was the year in 
which the first definite recommendations were 
made to provide such traps with vent pipes. 
The 1875 to '76 report of the Board of Health 
of the City of Brooklyn states that "Running 
traps for basins, sinks and tubs are unsafe and 



PLUMBING FIXTURE TRAPS 



should never be used without a vent pipe from 
their highest point to the open air." 

Colonel George E. Waring also recognized 
in 1878 the necessity of venting traps as well 
as waste pipes, by saying: 

"Such traps as are needed may be placed so 
close to the outlets which they guard that the 
length of intervening pipe shall be too little 
for the decomposition of its sliming to be 
noticeable. Every waste pipe may be venti- 
lated through its whole length from the soil 
pipe to the trap, that is by carrying an air 
pipe from the side of the house into the trap 
pipe a little above the water seal, and another 
pipe leading from the top of the receiver up 
alongside of the soil pipe out at the roof. This 
will secure a circulation of air at a point 
where it is very much needed and will much 
lessen the danger which we have to apprehend 
from kitchen sink and water closet traps as at 
present arranged." 

It is interesting to note that in the same 
year Col. Waring obtained a patent on a modi- 
fied % S trap with enlarged outlet body con- 
taining a float designed to prevent entrance of 
sewer air, very 'similar in construction to de- 
signs patented about 5 years earlier. 

In 1873 Patrick W. Doherty patented a 
"stench trap" very similar to that used by the 
U. S. Housing Corporation during the recent 
war and now manufactured by the Sanitary 
Company of America, under the name of the 
"Saaco Anti-Siphon Trap." 

In 1875 Ludwig Brandeis, of Brooklyn, de- 
veloped and obtained a patent on enlarging 
the body, but retaining the shape of the S 
trap. 

Many additional patents were issued under 
the names of: "Stench, Fluid, Plumbers*, 
Sewer Gas, Waste Pipe," traps since 1874, 
among which the following few may call for 
special mention: 

Chas. W. Garland, San Francisco, Cal., 1874 
and 1876. B. P. Bowers, Cleveland, Ohio, 

1877. George E. Waring, Jr., New York City, 

1878. Ludwig Brandeis, Brooklyn, Paragon 
Trap, 1878. Frank E. Cudell, 1878, 1886, 
1896, 1912. Joseph Bennor, Philadelphia, Pa., 
1880 (first Mercury Seal Trap). Frederick 
N. DuBois, New York, 1882. J. Pickering 
Putnam, Boston, Mass., 1884 (2 patents), 
1B87, 1897 and 1905. Samuel S. Hellyer, Lon- 
don, England, 1884. Hiram T. Bush, Detroit, 
Mich., Assignor to Ideal Mfg. Co., 1893. Leon- 
ard D. Hosford, Brooklyn, 1897. Albert S. 



Newton, Providence, R. I., 1898, 1907. George 
Cody, New York, Assignor to Louis Munziger, 
New York, 1904. (This trap is not the one 
now known as the "Geco" trap, but consisted 
of an S trap with enlarged cylindrical outlet 
leg, containing a baffle in front of the outlet 
pipe. The patentee claimed this trap to be 
"non-siphonable and self -scouring.") 

Among others are: Henry J. Luff, Cleveland, 
Ohio, 1908. George Cody, New York, March 
24, 1910. (This trap is now sold under the 
name of "Geco." It is described in the patent 
application as an "automatic anti-siphon self- 
scouring trap, having an inlet at the bottom 
and a horizontally extending outflow connec- 
tion from the top, the outer wall of the trap 
being extended inwardly at its junction with 
the outflow connection, and inclined continu- 
ously downward from said junction so as to 
form a combined cut-off lip and return water- 
shed when the trap is siphoning.") 

Since 1910 there have been issued about 
five patents on anti-siphon traps each year 
to various applicants, which are, however, less 
important than those mentioned above, for the 
purposes of this treatise. 

In 1879, on August 26th, a patent was is- 
sued to John McCloskey under No. 218,891 on 
improvements to sewer pipe connections, 
which covered the system of back-venting. 
McCloskey, being apparently of an aggressive 
disposition, took steps immediately to collect 
the royalty from D. P. Barhydt, for using 
back vents in his residence at 23 E. 41st street, 
New York, and suggested through his attor- 
ney, Frank J. Dupignac, of the Equitable 
Building, 120 Broadway, that he should settle 
for the sum of $50 per line of pipe used. Mr. 
Barhydt, undaunted, referred the matter to 
the Sanitary Engineer, now the Engineering 
News-Record, who had their patent attorney, 
J. N. Mclntire, investigate the pateni. Mr. 
Mclntire reported that in his opinion no one 
could be enjoined under the patent from the 
use of a venting system as then commonly em- 
ployed, and that the patent was perfectly in- 
valid. 

Another suit was brought by McCloskey 
against a householder on 54th street, James H. 
Young, for the use of his "patented venting 
system." It seems that the patentee had been 
employed as a journeyman plumber by Henry 
McGuckin, master plumber of 951 6th avenue, 
in the installation of the work during the sum- 



PLUMBING FIXTURE TRAPS 



mer of 1879, just prior to the issuance of his 
patent. 

Mr. Young refused to pay, and suit was 
brought in the U. S. Circuit Court, South- 
ern District of New York ; Betts, Atterbury and 
Betts were the defendant's attorneys and they 
retained Edward S, Philbrick, C.E., of Boston, 
Mass., as expert. 

Mr. Philbrick proved that he had used the 
venting system in 1875 in Brookline, Mass., 
and again in 1876 in the home of Dwight Fos- 
ter, 18 Chestnut street, Boston, Mass. Mr. 
Philbrick testified that he had been unable to 
find in the patent any point or combination 
which he as an engineer had not previously 
practised. 

The plaintiff finally withdrew the suit and 
paid the cost of the Court. 

It appears from the available literature, 
that in about 1880 the question was first 
raised seriously, whether anti-siphon traps 
could safely supplant vented traps of the %- 
S or S pattern. 

During this year Geo. E. Waring applied to 
the then existing National Board of Health foi 
an appropriation for experimenting on trap 
siphonage. This was granted, and the work 
was carried on with some degree of thorough- 
ness between June 6 and December 22, 1881, 
as stated by Col. Waring. Col. Waring goes 
on to say: 

"Subsequently I reported my results to the 
National Board of Health, and the report was 
put in type for publication in the 'Bulletin.' 
The publication was postponed for a time be- 
cause the results shown and the deductions 
drawn were not in accordance with the 
theories on which the prescriptions of several 
Boards of Health had been based." 

In these experiments Wm. Paul Gerhard 
assisted Col. Waring. The experiments, as 
described by Col. Waring, "in the interest of 
chronological exactness" in the "Sanitary En- 
gineer" of November 2, 1882, and stated by 
him to have been under the immediate super- 
vision of his assistant, William Paul Gerhard, 
C.E., were made in two different series. 

In series No. 1, the traps selected for test 
were attached with a "putty" joint to the end 
of a 1^/4-inch lead waste pipe connected into 
a 4 x 2 Y of the 4-inch cast iron soil pipe 
stack. The waste pipe was provided with 
three vent branches located at intermedi- 
ate distances between the trap and the stack; 



the vent branches could be opened or 
closed at will. The soil stack was about 
15^/^ feet high and extended at its foot by 
a bend and a 4-inch horizontal or inclined 
line. About 9 feet above the 4 x 2 Y branch 
was placed a bathtub with a 2-inch outlet and 
a 1%-inch lead waste pipe, discharging 80 
gallons from the tub in about 80 seconds 
through a 4 x 2 Y into the 4-inch stack at 
some distance, which is not shown, but prob- 
ably about 7 or 8 feet, above the lower 
4 X 2 Y. Still further up the stack, possibly 
a foot or so, although this is not stated in 
the records, a 4 x 4 Y was inserted, which 
received 2% gallons discharges from a funnel 
through a "Pan Water Closet" with a 4-inch 
lead trap having about 1-inch seal. The rate 
of discharge is not given. The top of the 
soil pipe was provided with a flap valve used 
to close the stack wholly or partially. Also a 
4-inch tinned iron pipe about 54 feet long 
with four bends was inserted at times into the 
top of the open 4-inch soil stack to provide 
additional length of stack. 

Five types of traps, namely the ordinary 
1^/4-inch S trap with seals varying from 3-inch 
to 5-inch, and made of glass; the Bowers trap 
having a ball floated against the inlet end; 
the Garland trap having a ball resting on the 
inlet by gravity; the Brandeis "Paragon" trap 
having an enlarged rectangular body, and the 
Nicholson mercury seal trap, were intended to 
be tested. The Cudell trap, another gravity 
ball trap, "arrived too late for trial," but "it 
seemed to be the same as the Garland trap." 

With the soil stack and vent branches closed, 
all the traps were completely siphoned, when 
only the bathtub full of water was discharged. 

With the soil stack closed, and one vent 
open, the maximum loss of seal of the S trap 
was 1 inch. The other traps were not experi- 
mented with. 

With the valve on top of the soil pipe %- 
inch open all around, the S trap lost 1%-inch 
water seal, when the bath and water closet 
were discharged simultaneously. Under the 
same conditions the two ball valve traps lost 
no water; the others were not tested. 

With the soil pipe open at the top and one 
of the vents open, the S trap and the two ball 
valve traps lost no water seal; the other traps 
were not tested. 

With the soil pipe lengthened 54 feet, open 
at the end, and no vent, water closet and bath- 
tub discharging simultaneously, the S trap 



PLUMBING FIXTURE TRAPS 



lost ^-inch seal, the Paragon trap %-inch; 
other traps were not tested. 

Under the same conditions, with the vent 
open, no loss of seal occurred in any trap; all 
traps were tested in this test. 

The second series of tests were made to de- 
termine if the flow of one fixture, such as a 
bathtub, would siphon the trap of another fix- 
ture, such as a basin, connected to the same 
waste pipe. In these tests a 1%-inch lead 
waste pipe with a bathtub at its upper end 
was connected into the 4 x 2 Y used in the 
previous series for the connection of the traps 
under test. The 1%-inch bath waste received 
a 1^-inch branch to which the various traps 
were connected for test, while the bathtub 
was being discharged. It was found that, 
whether the 4-inch soil stack was open or 
closed at the top made no difference; the un- 
vented S and Paragon traps were siphoned 
while the ball valve traps retained a sufficient 
water seal. The mercury seal trap was not 
tested. 

All of the experiments were made with the 
2-inch funnel-shaped bath outlet, which was 
then changed to 1%-inch and produced the 
same results. 

In his deductions, Col. "Waring states that 
the opening of the 4-inch soil pipe at the top 
practically prevents suction in the soil pipe, 
even when the upper part of the pipe is 70 feet 
in length; that the siphoning of even unvented 
%-S traps having more than 1 inch of seal 
need not be apprehended, if each fixture 
wastes by an independent outlet to a branch 
of a 4-inch soil pipe open at the top; that, if 
one fixture waste is connected as a branch to 
another fixture waste pipe, discharging into a 
soil stack, the discharge of the latter fixture 
may nearly or quite break the seal of an S 
trap on the former, unless of unusual depth; 
that under such conditions the seal of traps 
with balls, tested by him was not broken ; that 
under the same conditions the trap with an 
enlarged body tested by him was not superior 
to the ordinary S trap. 

He drew the general conclusion that the 
separate ventilation of traps, where the main 
soil pipe is 4-inch in diameter and open at the 
top, is unnecessary, especially "as it is always 
simpler and much less expensive to carry each 
waste independently to a branch of the soil 
pipe.'* 

However much Col. Waring may have been 
searching for the truth, it is impossible to 



grant that he found it, as will be readily seen 
in the light of present-day knowledge. No 
plumbing code of any city, however slack, 
would today approve of a system of plumbing 
with a 4-inch soil stack open at the top ex- 
tending 70 feet above the highest fixture, and 
receiving by individual branch wastes the dis- 
charges from unvented fixture traps of the %- 
S or S pattern. They would insist on either 
vented traps of the S or ^/^-S pattern or on the 
installation of such anti-siphon traps as they 
might consider proper. Even those who ad- 
vocate the use of anti-siphon traps in place 
of vented traps of the S pattern would concede 
that unvented S or %-S traps would be unsafe 
under such conditions. 

The Colonel's suggestion that each fixture 
be connected by a separate waste pipe into the 
soil pipe stack, is impracticable for reasons of 
building construction. 

It is fair to conclude from the deductions 
made by Col. "Waring that, where it is impos- 
sible to provide individual waste pipes to the 
soil stack from each fixture, and where it be- 
comes necessary therefore to use the same 
branch waste pipe for two or more fixtures, 
the only alternative is the use of traps with a 
floating or gravity ball or similar device. 
Nearly all standard plumbing codes and all 
reputable sanitary engineers will prohibit, in 
the light of present knowledge, the use of 
traps with balls or similar mechanical devices. 
Hence I am satisfied that experience has 
proven Col. Waring's conclusions to be erro- 
neous in two particulars, to say the least. 

I do not believe that Col. "Waring drew in- 
tentionally any conclusions favoring ball traps, 
but it is the fact that he was the patentee of 
a trap containing a mechanical device of a 
similar type. 

A comparison made between the siphonage 
resisting qualities of the vented S trap and the 
unvented anti-siphon traps in the "Waring tests 
shows that the former could not be siphoned 
even with the soil stack completely closed at 
the roof, while the latter, even those with the 
ball valves, failed completely under the same 
conditions. 

So far as I am able to ascertain, the Na- 
tional Board of Health, for whom the tests 
had been conducted, never published Col. 
"Waring's report. 

In 1882, S. S. Hellyer, of London, England, 
conducted an interesting series of trap siphon- 
age experiments, which are described in the 



PLUMBING FIXTURE TRAPS 



Sanitary Engineer^ issue of August 17, 1882, 
Vol. VI. These tests were made with 1%- 
inch, 2-inch, 3-inch and 3^-inch stacks, slop 
sinks, baths, lavatories and water closets, and 
with %-S, Bowers, Anti-D, Anti-D Narrow 
Band, Helmet and Eclipse traps. 

The experiments were very comprehensive 
and made with fixtures on three floors, the 
total height of stacks varying between 37 and 
70 feet. The vent pipes were controlled by 
valves. Mr. Hellyer, whose experiments are 
referrd to by Dr. Wm. Paul Gerhard in his 
"Sanitary Engineering of Buildings," as care- 
ful and valuable, concludes that, "Where tiers 
of traps of any description are fixed upon one 
main pipe, for receiving discharges from 
water closets, slop sinks, baths, quick waste 
lavatories, etc., each individual trap or branch 
must be ventilated, if the traps upon the pip- 
ing are to maintain their seals intact." 

It is obvious that the conclusions drawn by 
Mr. Hellyer are diametrically opposed to those 
drawn by Col. Waring, and it is interesting to 
note that Dr. Gerhard, who conducted the 
Waring tests, considers the Hellyer tests as 
"careful and valuable." 

Attention is called to the fact that Mr. 
' Hellyer held an English patent on the Anti-D 
trap since March 25, 1880, and the American 
patent on the same trap was issued to him on 
October 10, 1884, two years after his tests re- 
ferred to above. 

In 1882 Messrs. Ernest W. Bowditch, C.E., 
and Edward S. Philbrick, C.E., of Boston, 
were retained by the National Board of Health 
to "conduct sundry experiments, to test the 
efficacy of various styles of traps used upon 
house drains under the varying circumstances 
and conditions to which they are subject in 
ordinary use, especially with a view to ascer- 
tain the liability of such traps to lose their 
water seal by siphon action." These experi- 
ments were conducted in the Mechanics Hall, 
Boston, Mass. 

The apparatus consisted of vertical typical 
2-inch and 4-inch stacks, extending 57% feet 
above the basement floor, with branches in the 
basement and on the floors above, and having 
the upper end open 8 feet 3 inches above the 
upper floor. The stacks extended down to a 
point 2 feet above the basement floor, from 
which they turned to a slope of 2 feet in 32 
feet. The 2-inch stack was connected into 
the 4-inch at a distance of 5% feet from the 
bend along the horizontal run. A 4-inch run- 



ning trap and fresh air inlet were provided at 
the end of the 4-inch line. 

Fixtures, including water closets, bathtub 
and slop hopper, were connected and dis- 
charged into stacks on various floors; branches 
were provided for attaching the traps under 
tests; trap vent pipes were installed in the- 
shape of pipe coils laid on the floor, and the 
traps tested were the S, the Adee, Cudell, 
Bowers and pot or round trap. The tests are 
described in detail in Vol. VI, 1882, August 
31, issue of the Sanitary Engineer. 

Among the conclusions drawn by Messrs. 
Philbrick and Bowditch were the following: 
"The ordinary S trap alone with ample air 
vent is therefore recommended for use under 
water closets, and also for all other fixtures, 
when its proper ventilation can be secured 
within reasonable limits of expense. The 
proper size and length of such vent pipes 
must be largely a matter of judgment. 

"Whenever branch inlets are connected to 
a line of waste or soil pipe that is vertical or 
approaching that direction, above which 
branches other fijctures are used for discharg- 
ing water into the same main, there is great 
risk of losing water from the traps attached 
to such branches, whenever the upper fixtures 
are used. No form of trap has come to our 
attention without special air vent which is not 
likely to lose water seal under such circum- 
stances, even when the top of waste or soil 
pipe is open, except those which, like the 
round trap, are objectionable for retaining 
filth. The writer has seen them so far en- 
cumbered with grease as to lose most of those 
advantages and the ability to retain water 
seal. We can, therefore, recommend with less 
reservation the use of a well-ventilated S trap, 
wherever the vent pipe can be applied without 
unreasonable cost. The best and most simple 
remedy for the siphoning of traps, in most 
cases, is undoubtedly to be found in the in- 
troduction of air at the normal pressure at the 
crown of the trap. 

"There is still another risk arising from 
change of air pressure in drains besides that 
of siphoning traps. The latter is the result 
of lack of pressure, while an excess of pres- 
sure is also to be avoided." 

Experiments made by the investigators are 
cited, which resulted in the forcible eiection 
of "water and foul drain air" from a base- 
ment trap. 
The National Board of Health, to whom 



PLUMBING FIXTURE TRAPS 



the report was made, had as its members the 
surgeon-general of the U. S. Army, the medi- 
cal director of the U. S. Navy, the solicitor 
general, medical representatives of the U. S. 
Marine Hospital Service and of the Army and 
Navy, and seven physicians in private practice 
from New York, Boston, Washington, Chicago, 
Memphis, etc. 

In 1884, J. Pickering Putnam, architect, of 
Boston, Mass., claims to have been retained 
by the Boston City Board of Health to experi- 
ment and report on trap siphonage and evap- 
oration. His report, as published in the 1911 
edition of his book, "Plumbing and House- 
hold Sanitation," is signed by himself and by 
L. Frederick Rice. The same report, signed 
by both, appeared also in the American ArchU 
tect and Building News of June 7, 1884. 

Henry C. Meyer, the well-known editor of 
the Sanitary Engineer, who was always vitally 
interested in all matters pertaining to sanita- 
tion and public health, reviewed ' the report 
in the August 7th issue of 1884, as follows: 

"The paper relates at length a series of 
experiments made upon traps of various pat- 
terns with the author's deductions. As the 
deductions are at variance with those arrived 
at by E. S. Philbrick, member of the Ameri- 
can Society of Civil Engineers, and E. W. 
Bowditch, published in these columns in the 
report of these gentlemen to the National 
Board of Health, and as it tends to show the 
practice of ventilating traps to be a great mis- 
take, we have taken some pains to inquire 
into the nature of the investigation and the 
amount of weight to be attached to the de- 
ductions. 

"We find that Mr. Rice was not known by 
the Boston Board of Health to have taken 
part in the investigation, nor did this Board 
employ Mr. Putnam for that purpose. The 
idea originated apparently with Mr. Putnam, 
who, it seems, had invented and patented a 
new device for a trap and wished to test its 
merits as compared with other traps. He 
therefore applied to the Boston Board of 
Health, stating that he wished to make some 
experiments, but without mentioning that he 
had a patent of his own, and asked for aid in 
defraying the expense of necessary apparatus. 
The Board, wishing to make certain tests as to 
the efficiency of "bottle" or "pot" traps, offered 
aid to a limited extent for the sake of getting 
further information on this particular sub- 
ject and no other, but the Board, not being 



personally acquainted with Mr. Putnam, told 
him that the experiments must all be con- 
ducted in the presence of Mr. Philbrick and 
Mr. Bowditch. 

"These gentlemen were therefore notified 
and were present at a portion of the tests. 
But after the first test, which they witnessed, 
they were convinced that the apparatus used 
was not a fair type of ordinary good prac- 
tice, and so informed Mr, Putnam. Mr. Phil- 
brick also wrote him under date of January 
18, 1884: 

"It seems to me that it is a very plain case 
that there is no practicable risk of having 
your new trap or either of the larger sizes of 
the Bottle trap lose their seal by siphon ac- 
tion, while new and clean, or in any condition 
which they are not likely to be subjected to 
in actual use. This being admitted, it does 
not seem to me of any use or of interest to 
the public in any way to continue the experi- 
ments in that line. In short, since we do not 
regard the loss of water seal in these traps 
when clean as their weak point, why trouble 
ourselves any more on such remote possibili- 
ties? Neither do I think it possible, by any 
series of laboratory tests, to develop the weak 
points in this class of traps, because I con- 
sider that weak point to be their liability to 
collect filth, with the several evils indirectly 
arising from such results. 

"I think, however, that the loss of trap 
water by evaporation is an important subject 
for investigation, and will try to get up a pro- 
gram for that with Mr. Bowditch as requested. 
"(Signed) Edward S. Philbrick." 

"The Putnam report to the Boston Board of 
Health was submitted to Mr. Philbrick with 
request that they should sign it, which they 
declined to do for the reason that they con- 
sidered that his deductions were not war- 
ranted by the results. . . . The chairman 
of the Board was surprised to find that the re- 
port presented in a prominent manner the 
patent traps of Mr, Putnam, of which he had 
never heard when agreeing to assist him with 
money, and advised Mr. Putnam to omit all 
mention of that device. This suggestion was 
not adopted, however. 

"Now, while Mr. Putnam is respected so far 
as we can learn, as an honest and upright 
man, we regret that such an investigation, 
which might in the hands of a man without 
the bias of self-interest, have produced re- 
sults of more value, should have been com- 



PLUMBING FIXTURE TRAPS 



mitted to any one who had an axe to grind 
for himself in the same connection. This cer- 
tainly would not have happened if the Board 
of Health had understood the fact that Mr. 
Putnam had a patent trap which he wished to 
test and bring into notice. The deductions 
of Mr. Putnam concerning inefficiency of ordi- 
nary vented S traps to resist loss of water by 
siphon action seemed to be vitiated by the 
fact that the apparatus he employed does not 
fairly represent ordinary practice. The com- 
bination is as follows: 

"A vertical soil pipe over 70 feet in height 
without crook or offset to break the fall; near 
the top a Plunger water closet having a 
charge of 4% gallons; 40 feet below this 
point a 4 X 4 Y branch, the inserted hub of 
which was capped and in the cap a 1%-inch 
waste pipe inserted, to the end of which the 
traps to be tested were successively applied. 
The fall of 4% gallons passed the Y branch 
with such high velocity that a considerable 
vacuum was produced. The water seal of 
1^/4 -inch S trap was broken after three sue- . 
cessive discharges, although trap was pro- 
vided with 1^-inch vent 17 feet long. A 
single discharge of the water closet, while the 
bath waste was running, on the same floor, 
broke the seal of the same trap when the same 
vent was attached." 

"Mr. Putnam used a 4x4 Y branch capped, 
in which cap a small waste was inserted. This 
peculiar joint increased the siphoning power 
of a passing column of water some four fold, 
if not more, above what it would have been 
with a 4x2 Y. The power of a charge falling 
in the vertical pipe, to disturb the water in 
any trap attached to the branch, past which it 
rushes, depends on the following elements: 

1. The volume of water passing such 
branch orifice. 

2. Its velocity. 

3. Size of side opening on branch. 

4. The cubic capacity of the branch itself 
below the trap. 

"It is evident to any one who has watched 
such an apparatus in operatipn that the power 
to disturb the water in the trap on the branch 
waste arises not from the vacuum in the ver- 
tical pipe above the falling water, for the 
effect is made manifest before this mass of 
water seven feet or more in length has com- 
pletely passed the opening and before the time 
has elapsed to establish communication between 
the air in the branch waste and that above the 



falling charge of water. The effect is certain- 
ly due to the air which was previously in the 
branch being forcibly torn out by the water 
which rushes past it. This action is certainly 
just in proportion to the size of the side open- 
ing in the vertical pipe, and this is 4 times as 
large in a 4x4 Y as it is. in a 4x2 Y. But the 
amount of disturbance of the trap water de- 
pends not only on the degree of vacuum pro- 
duced below it, but also on the volume or 
cubic capacity of the chamber in which such 
vacuum exists, i. e., on the quantity, of air 
which it is necessary to force through the 
trap to supply the vacuum and establish an 
equilibrium. 

"The criticisms we have made tend to show 
the importance of having all investigations of 
natural laws condticted by thoroughly edu- 
cated physicists who are quite independent of 
a basis of self-interest; for, however candid a 
man may try to be, human nature is known 
to be too fallible and nature's laws too ob- 
scure to be fathomed by any but the most 
independent investigators." 

It is unnecessary for me to further question 
Mr. Putnam's report. Mr. Meyer performed 
this task at considerable length, as shown by 
the foregoing quotations from his periodical. 
I believe, however, that before passing on to 
further tests, it is pertinent to look into Mr. 
Putnam's general scientific mental attitude on 
sanitary questions, as revealed in his writings. 
I am not surprised to find in his book pre- 
viously referred to, published as recently as 
1911 and entitled "Plumbing and Household 
Sanitation," that he is the inventor of and 
devotes a whole chapter of 24 pages to the 
description of a cast iron pipe joint made 
tight with "a composition which has about the 
consistency of fresh putty when in the condi- 
tion used by glaziers, with three very impor- 
tant other qualities, the first being a perma- 
nent plasticity due to the combination in the 
substance of a special form of non drying oil, 
etc." I find further that "sunlight is hostile to 
disease germs, but modern science has demon- 
strated that germs are, as we have seen, 
equally hostile to sewers and plumbing pipes, 
so that it is now knovm to be no longer re- 
quired for bathrooms." Also on the same 
subject: "Proper artificial lighting is actually 
preferable." 

But the worst of all : "In its fresh state 
sewage forms a useful food for fish." 

The master plumbers of Boston, it would 



8 



PLUMBING FIXTURE TRAPS 



seem, were not satisfied with the tests and 
report by the patentee of the Sanitas trap, 
any more than Messrs. Philbrick and Bow- 
ditch or the Boston City Board of Health, for 
in 1885 they decided to experiment on their 
own hook under the auspices of the Board 
of Health and under the direction of a com- 
mittee of the association, of which J. 0. Sisson 
was chairman. 

The tests seem to have been made in the 
Pierce block in Worcester, Mass. The ap- 
paratus consisted of a vertical 2-inch pipe, 
about 50 feet long, with a horizontal discharge 
pipe, 14 feet long, at its bottom to the sewer. 
The top of the 2-inch vertical pipe was con- 
nected into the bottom of a tank of such size 
that 2% inches of water in depth amounted 
to 5 gallons. The 2-inch tank outlet was fitted 
with a 2-inch hand operated flush valve. A 
2-inch Y branch was inserted in the 2-inch 
vertical pipe at a point 14 feet 3 inches below 
the tank bottom. To this Y the traps to be 
tested were attached by a threaded nipple, 
which had a valved ventilating connection 
with a 1^-inch clear circular opening ex- 
tended with 10 feet of 1%-inch vent pipe. 

The traps tested were the Sanitas, Bowers, 
Cudell, Bennor, Bottle, Round and S traps. 
The tests applied consisted of successive 5- 
gallon flushes from the tank without refilling 
the traps. 

With the Vent Connection Closed— The 
Cudell, Bowers and Bennor traps were com- 
pletely unsealed after the first discharge. 

The Bottle trap, 2% inches diameter, 7 
inches high, with 3% inches depth of seal, 
was unsealed by the third flush. 

The Sanitas trap had only a total of ^/^ gill 
of water and only 6 drachms left above the 
seal after the third flush. 

The Round trap, 5^ inches diameter, ^ 
inches high, with AV2 inches depth of seal, 
holding 2^ quarts, retained 16 ounces of 
water above the seal after 15 or 20 flushes. 

With the Vent Connection Open — ^The S 
trap water seal was not disturbed. 

The above-mentioned tests are described 
fully in the Sanitary Engineer of September 
10, 1885. It is interesting to note that J. 
Pickering Putnam claims in his book "Plumb- 
ing and Household Sanitation," page 258, 1911 
edition, that the seal of the S trap was "broken 
when ventilated through the 1%-inch vent 
next the soil pipe." 

Mr. Putnam should have known that he was 



in error, since he wrote on the same subject 
in September, 1885, to the Sanitary Engineer, 
the editor of which, Chas. F. Wingate, replied 
to him under date of October 1, 1885, calling 
his attention to the fact that the test report 
was correct, it having been furnished him by 
the chairman of the testing committee. 

In 1886, Wm. E. Hoyt, C.E., S.B., chief engi- 
neer of the Buffalo, Rochester and Pittsburgh 
R. R. Company, delivered an address on house- 
hold sanitation before the Rochester Academy 
of Sciences, in which he described tests on 
trap siphonage made by J. Pickering Putnam 
at the Massachusetts Institute of Technology 
in Boston. The testing apparatus was unique 
and ingeniously designed, unquestionably 
favoring the siphonage of vented traps. It 
was constructed, as described and shown in a 
cut in Mr. Putnam's much mentioned book, of 
a 4-inch soil and 2-inch vent pipe stack, the 
former having connected to it two water clos- 
ets and about 10 feet lower a Y branch to 
which the waste pipe was attached with the S 
trap to be tested. Each of the two stacks 
were about 90 feet long made up of coils of 
six vertical loops of about 15 feet each with 
return bends at the end of each loop. The 
end of the 2-inch vent coil was connected into 
the 4-inch soil pipe coil at about its middle 
point by means of an inverted 4x2 Y, so that 
the inrushing air had to pass around this very 
sharp turn and in addition through 10 feet of 
small vent pipe of unknown size, 90 feet of 2- 
inch vent pipe, 45 feet of 4-inch pipe, six 2- 
inch return bends, one 2-inch quarter bend, 
three 4-inch return bends and one 2-inch quar- 
ter bend. 

The "inverted" Y branch produced, of 
course, a faulty installation, since it practi- 
cally forced the 2-inch venting system to at- 
tempt to draw its supply of air from the 4- 
inch soil pipe between this Y and the water 
closets, in which the air was already rarefied 
by the water closet discharges. What sane 
man, attempting to design a reasonably good 
plumbing system, would re-connect a 2-inch 
vent stack into a 4-inch soil stack by means of 
a 4x2 Y branch with the branch pointing 
downward? 

This is not all. The S trap under test had 
its inlet pipe connected into the 2-inch vent 
stack, that is, it was vented on the house side. 
No other vent was provided from either the 
waste or the trap. No wonder that the trap 
could be easily siphoned. 



PLUMBING FIXTURE TRAPS 



Nothing could have been done which would 
have more positively produced siphonage of 
the S trap than this, and which would have 
tended to mislead any but those thoroughly 
acquainted with the science of venting. 

In December, 1886, Glenn Brown, architect, 
of Washington, D. C, read before the Ameri- 
can Institute of Architects at its 20th annual 
convention a paper, describing a series of tests 
made on anti-siphon and S traps at the 
Museum of Hygiene, U. S. Navy Department, 
Washington, D. C. In his introductory re- 
marks he says the following: 

"The experiments on trap siphonage made 
by S. S. Hellyer, of London, and similar ex- 
periments conducted by Philbrick and Bow- 
ditch, of Boston, clearly proved the utility of 
trap ventilation. The reports of Geo. E. War- 
ing, of Newport, and J. Pickering Putnam, of 
Boston, as clearly (apparently) proved the 
uselessness of such ventilation. In the prep- 
aration, of a work on Plumbing I found this 
conflict of authorities very perplexing. In 
fact, it was impossible for any one to form a 
definite conclusion on the eflficiency or ineffi- 
ciency of trap ventilation without actual ex- 
periment. 

"The difl5culty and object to be attained 
were laid before Dr. J. Mills Browne, medical 
director, U. S. Navy, in charge of the Museum 
of Hygiene at that time. Upon consulting 
with the Surgeon General of the Navy, the 
subject was thought of sufficient importance 
to have a system of iron and lead pipes with 
fixtures erected outside of the Museum Build- 
ing. With these pipes I have conducted ex- 
periments from the fall of 1885 to the present 
time as opportunity would permit. The waste 
and vent pipes are of the sizes used and ar- 
ranged as in common practice. The traps, on 
which the tests were made, were selected so 
as to cover the different kinds in the market, 
both mechanical and non-mechanical. The 
apparatus is so arranged that fixtures can be 
subjected to a strain equal to what they would 
receive in actual use, as well as strains more 
severe than they would have to withstand, ex- 
cept in unusual contingencies. 

"The points of inspection and for attach- 
ment of traps, are platforms located on first, 
second, third and fourth stories, as shown in 
drawing attached. By this arrangement the 
effect of water discharged from varying heights 
can be thoroughly tested in their relation to 
different stories of a building. There is a 



marked change in the effect produced in dif- 
ferent stories of a building by a discharge 
of water from the same point. 

"The main stack is of 4-inch extra heavy 
cast iron, starting at a connection with the 
sewer and running thence a distance of 32 
feet horizontally, and 42 feet vertically to a 
point above the roof of the building. In the 
second story there is an auxiliary stack of 4- 
inch lead pipe connected with the iron pipe 
and running to a point above the roof. Both 
of the iron and lead pipes have running traps 
and fresh air inlets near their point of com- 
mencement with valves and screw plugs, by 
which they can be partially or completely 
closed as desired. By means of a Y branch 
the system can be made to empty into the 
sewer without passing these running traps. 
Either outlet can be used at pleasure, both 
being governed by gate valves. 

"Two stacks of 3-inch vent pipe, one of iron 
and the other of lead, run vertically from the 
second story to the roof, thence horizontally 
along the roof. By means of plugs and valves, 
the lengths of vents may be varied from a few 
feet to 42 feet and openings from to 3 inches. 
The outlets in both soil and vent pipes are so 
arranged that traps from l^/i-inch to 4-inch 
can be attached at pleasure, all outlets not in 
use being cut off by gate valves or screw plugs. 

"Siphonage caused by the discharge of 
water through the trap itself from a fixture 
above has been found of very little conse- 
quence. Siphonage rarely takes place; the 
water passing over the long arm of the siphon 
rarely fills the pipe so as to cause the neces- 
sary vacuum. When it does take place, the 
trap fills by drainage from the fixture above. 
Back pressure which comes from sewers would 
never force the seal of the trap in a house 
plumbed according to modern practice, the 
fresh air inlet and the top of the soil pipe 
being always left open. 

"The greatest danger arises from the dis- 
charge of large bodies of water down long 
vertical 4-inch pipes. This column acts to a 
certain extent like a piston, compressing air 
in front of it, and creating a vacuum behind. 
The air rushing in to fill the vacuum, forces 
or drains the water from the trap into the soil 
pipe, while compressed air finds its easiest 
mode of escape through the traps below the 
point of discharge, even when there is a fresh 
air opening between the running trap and the 
house. Although water in case of back pres- 



10 



PLUMBING FIXTURE TRAPS 



sure is drawn up into the pipe or fixture above 
the trap and then returns to the trap, the 
sewer air passes into the house. 

"The majority of experiments have been 
made to test the power of the traps to resist 
siphonage and back pressure produced by the 
column of water passing down the vertical 
pipes. The question of first importance is: 
Does ventilation protect the seal of traps in 
ordinary use? This question is answered by 
the following experiments, in all of which the 
vent pipes were open, and a positive effort 
was made to break the seal of the trap.** 

Any one interested in the detail experiments 
is referred to the Sanitary Engineer, Vol. 15, 
December 11, 1886, which says of the in- 
vestigation : 

"Such disinterested work as is here re- 
ported is very creditable. Moreover, it is of 
value, since the investigations were evidently 
conducted to get at the real facts; no unusual 
conditions were arranged, and no misleading 
conclusions are drawn. As was to have been 
expected, the results of Philbrick and Bow- 
ditch in their investigation for the National 
Board of Health have again been reached. 
Mr. Brown, like Messrs. Philbrick and Bow- 
ditch, had no commercial interests to serve by 
securing special results; consequently his ex- 
periments were fairly and intelligently con- 
ducted and his conclusions are entitled to 
consideration." 

Mr. Brown states in his recapitulation: 
"I conclude. Traps, when properly vented, 
are not siphonable. It has been asserted that, 
when the vent is placed on the crown of the 
trap, in time it becomes choked by refuse 
matter adhering to the surface. In these ex- 
periments the vent has been put in different 
positions and it makes no difference in its 
effectiveness, as long as it is between the trap 
and the vertical soil pipe. With a little care 
the Y can be so placed and shaped that the 
matter passing through the pipe would not 
adhere to the vent.** 

J. Pickering Putnam dismisses Mr. Brown's 
tests in his previously mentioned book with 
the words: 

"Another illustration of trap testing ap- 
paratus, upon which interesting experiments 
on siphonage have been made, is given in Fig. 
263. This apparatus was used at the Museum 
of Hygiene, U. S. Navy Department, at Wash- 
ington, and they showed substantially the 
same results as the experiments already de- 



scribed.'* The author fails to even mention 
the name of the investigator. 

So far as I am able to ascertain facts with 
regard to conditions in New York City be- 
tween 1880 and 1890, I find that the first 
"Law and Regulations Governing the Plumb- 
ing and Drainage of All Buildings Hereafter 
Erected," were enacted by the New York City 
Health Department on April 3, 1883, on au- 
thorization by the State Legislature in Chapter 
450, Laws of 1881, passed June 4, 1881. 

Great credit is due to Dr. Charles F. Chand« 
ler, who was president of the New York City 
Board of Health from 1873 to 1884, inclusive. 
The regulations provided that "Traps must be 
protected from siphonage, and the waste pipes 
leading from them ventilated by a special air 
pipe, in no case less than 2 inches in diameter 
for water closet traps, and 1^ inches for 
other traps"; also "That every water closet, 
urinal, sink, basin, washtray, bath and every 
tub or set of tubs must be separately . and 
effectively trapped." No particular type of 
trap seems to have been prescribed. 

While no record appears to be available of 
the tests on which these regulations had been 
based, I consulted Dr. Chandler personally to 
ascertain what steps had been taken by him 
in this respect prior to the preparation of the 
"code." Dr. Chandler, who is perhaps in these 
days better known as Professor Chandler of 
Columbia University, told me that he had, as 
president of the Board of Health, obtained an 
appropriation from the city for experimental 
plumbing tests, and that he had caused to be 
installed an actual plumbing system in the 
New York City Board of Health office in the 
eighties for testing purposes, which system, he 
said, was fitted with glass traps. 

He concluded from his experiments that the 
protection of the health of the people of New 
York City demanded the back-venting of each 
fixture trap. Professor Chandler expressed 
it as his opinion that the general introduc- 
tion of unvented anti-siphon traps in New 
York City would be most unfortunate and 
ill-considered, because of their tendency to 
foul, their subsequent loss of siphonage re- 
sisting qualities, the danger of back pressure 
with resulting "blowing" of traps, in plumbing 
systems without back air pipes, and the in- 
creasing menace of pipe corrosion which will 
necessarily follow the decrease in pipe ventila- 
tion. 

Tests of anti-siphon traps have been made 



PLUMBING FIXTURE TRAPS 



11 



or witnessed by the chief plumbing inspectors 
of various cities, but they have, as a rule, not 
been published. I have made inquiry by cor- 
respondence with the chief plumbing inspec- 
tors of about 185 cities in this country exceed- 
ing 35,000 population as estimated from the 
U. S. Census, what, if any, trap tests had been 
made or witnessed by them. Ninety replies 
were received, of which 16 were affirmative, 
the balance negative. Out of these 16, there 
are 13 which, apparently because of the test 
results, prohibit the general use of unvented 
anti-siphon traps, namely: Newark, N. J.; 
Elizabeth, N. J.; Elmira, N. Y.; Altoona, Pa.; 
Worcester, Mass.; Akron, Ohio; Cleveland, 
Ohio; Chicago, 111.; Washington, D. C; 
Davenport, Iowa; Oakland, Cal.; San Antonio, 
Texas, and Portland, Ore., with a total re- 
ported population of about 5,925,000 people. 

The three cities, in which tests were re- 
ported to have been made, and which now per- 
mit the use of certain unvented anti-siphon 
traps, but also under restrictions as to dis- 
tance from the soil or waste stack, are: Hol- 
yoke, Mass.; Springfield, Mass., and Richmond, 
Va., with a total reported population of only 
about 365,000 people. 

The anti-siphon traps which were approved 
on the basis of the tests in one or more of the 
three cities mentioned are: The Connolly, 
Dome or Drum, Newton, Sanitas, McAulifFe, 
Positive, Radcliffe, Imco, Wolverine, Hajoca, 
Monarch, Femco, Paragon and Novis. 

While the city of Springfield, Mass., ap- 
proved 13 different anti-siphon traps for use, 
the chief plumbing inspector, Frank W. Tower, 
states that the experience in Springfield with 
10 of the approved traps has been so unsatis- 
factory that their use has been discontinued. 
It should be noted that the "Geco" trap, which 
the Board of Standards and Appeals has 
approved for use in New York City, is not 
included in the traps which were approved by 
the three cities named. 

It would be too lengthy to describe in de- 
tail all of the tests reported to me to have 
been made or witnessed by the chief plumbing 
inspectors of the 16 cities, but the tests made 
for Chicago, 111.; Davenport, Iowa; Washing- 
ton, D. C; Cleveland, Ohio; Elmira, N. Y.; 
Richmond, Va. ; Springfield and Holyoke, 
Mass., are of particular interest, and are there- 
fore hereinafter briefly explained. In addition 
thereto, tests made for the students of the In- 
ternational Correspondence School at Scran- 



ton, under the direction of T. N. Thomson, 
consulting engineer, also one he observed in 
Wilkesbarre, Pa., should be briefly referred to. 
The city of Rochester, N. Y., has also, perhaps 
more extensively than other cities of its size, 
conducted tests on anti-siphon traps which will 
be considered more in detail hereafter. 

Chicago^ III^ tests reported from memory 
by Thomas J. Claffy, assistant sanitary inspec- 
tor. Tests were made in 1906 under the super- 
vision of Chief Sanitary Inspector Perry L. 
Hedrich on the following traps: Sanitas, Clow, 
Whiteford, L. Wolff Mfg. Co. 

*'A tank containing at least 15 gallons of 
water was connected to a vertical 1%-inch 
waste pipe with a quick opening valve near 
the bottom of the tank. About 10 feet below 
the tank a l*/^-inch tee was placed to which 
the traps to be tested were connected. A ver- 
tical extension of about 20 feet was connected 
to this tee and emptied into a trough below. 
The trap was filled with water to the level of 
its outlet and the depth of the seal measured. 
By opening the valve wide and emptying the 
tank, the vacuum was formed in a long waste 
pipe and the loss of trap seal varied from %- 
inch to 1^/4-inch. Repeated discharges from 
the tank lowered the trap seal to almost the 
vanishing point in some traps." 

Richmond, Va., reported by Thomas M. 
Landers, chief plumbing inspector: "The first 
anti-siphon trap that was tested was a New- 
ton trap, manufactured by the Providence 
Steam Trap Co., of Providence, R. I., about 
20 years ago. This trap was tested at their 
factory in Providence at that time under my 
personal inspection. 

"As a description of the test made, I will 
say that there was a large tank erected on the 
roof of the building and elevated with a capac- 
ity of, say, about 75 gallons, filled with water. 
Connected to the bottom of the tank was a 
l^/^-inch iron pipe, say about 40 or 50 feet in 
length, extending to the yard below. To the 
best of my memory, the pipe ran across the 
roof of the building some distance, with 2 ells, 
to get to the outside of the building, and 
thence down the side of the building to the 
yard below. About two feet below the bottom 
of the tank was inserted a quick opening valve 
with lever handle. About a foot or so below 
the valve there was installed a Y branch, and 
into this was screwed a 1%-inch Newton P 
trap with a Mica window soldered to the por- 
tion of the trap on the outside that holds its 



12 



PLUMBING FIXTURE TRAPS 



seal. The quick opening valve was then 
opened full, and the pressure of water from 
the tank flowed through the pipe, and the 
effect of the action of the water seal on the 
trap was watched. It was found, after several 
tests of this kind were made, that the seal was 
not broken, and it was impossible to break the 
seal. Naturally, in testing an anti-siphon trap, 
some of the water seal may be lost in making 
the test. In fact, all I have ever tested, would 
lose a little of the seal, but not sufficient to 
break it. 

"This is a description of how our first trap 
was tested out, and all the other traps that the 
Plumbers' Examining Board and myself have 
approved, were tested in a manner similar to 
that, but they were all tested here in this city 
of Richmond." 

Davenport, Iowa. Tests reported by Otto 
Meinert, inspector of plumbing, as follows: 
"One of the tests was made by installing a 
line of 1^/4-inch pipe, connecting a lavatory 
on the first floor and on the second floor, and 
filling the bowls with water and discharging 
them at the same time, and both of, the traps 
siphoned, using the Bowers anti-siphon trap. 

"Another time a 1^2 -inch pipe was used and 
the same result occurred. On another occa- 
sion I connected an anti-siphon trap to a bath- 
tub and filled same with water, and when it 
was discharged the trap had siphoned. 

"In another case, a sink was installed with 
one of these traps, which was 14 feet from a 
2-inch vent stack going through the roof on a 
one-story building, and when the sink was 
filled with water this trap siphoned. This 
would always happen on wash days, and from 
all of these experiences I am more than satis- 
fied that there is nothing like the pipe traps 
which are vented." 

Washington, D. C. Tests reported by A. R. 
McGonegal, inspector of plumbing, office of 
the Engineer Commissioner of the District of 
Columbia, as follows: It is perhaps regret- 
table that we have kept no record of tests of 
anti-siphon traps, but the idea we had in mind 
was two fold: 

"1. Not to have a written record which 
might crop up some time to embarrass the 
•manufacturer of a trap that failed, and 

"2. In case one did pass, not to have a 
written record which might be availed of for 
advertising purposes. Therefore, each trap 
was tested when submitted, usually in the 



presence of the manufacturer's representative, 
and he was told of its failure there. 

"The majority of the tests were made 
through the medium of an old tank and a V/2- 
inch galvanized pipe with a full opening valve 
(throttle type), a 1%-inch long turn recessed 
TY, 5 feet below the tank for connection of 
the trap, and 30 feet of 1^/^-inch galvanized 
pipe straight down v^rith a free opening at the 
bottom. The normal test consisted of three 
intermittent discharges of five seconds each, 
and any trap which failed to have half he 
regulation seal requirement (%-inch) left, 
was not passed. Two makes came pretty near 
passing, and at the request of their makers 
they were tested over and over again, but their 
average remained slightly under %-inch, 
therefore all were classed as failures. No 
tests or conditions were made or created rela- 
tive to back pressure. 

"For a short period, instead of the apparatus 
described above, we availed ourselves of the 
proximity of an air compression plant, and 
used a reducing valve and a direct blow of air 
on the fixture opening of the trap of 14% 
pounds, for 5 seconds, and the results were 
about the same as with the other. 

"I realize that there are occasions when it 
is an impossibility both financially and practi- 
cally to obtain a vent for a fixture found to 
be necessary, such as a basin in a barber shop 
in a many storied fireproof building, and a 
resealing trap is the remedy, if some compe- 
tent official could designate the manner of its 
connection so as to be assured of its air relief 
by two or more different lines, but even then 
their use is questionable." 

Cleveland, Ohio. Tests reported by Chas, 
A. Rainger, chief inspector of plumbing, as 
follows: "Some recent tests were made under 
the supervision of Henry J. Luff at the Case 
School of Applied Science, consisting of a 10- 
foot leg with a quick-acting valve on the ex- 
treme lower end, the trap being attached to 
the upper end, and the whole line and trap 
filled with water and discharged by opening 
the valve. 

"These tests I kept no record of, as I con- 
sidered that they were of no value, because of 
the fact that there was no discharge of water 
through the trap, but simply a discharge of 
water contained in the trap and line. The 
discharge line in this case was semi-vertical." 

Elmira, N. Y. Tests reported by Edgar E. 
Kroul, inspector of plumbing. Board of Health, 



PLUMBING FIXTURE TRAPS 



13 



as follows: "The test made here a number of 
years ago consisted of an oil barrel placed on 
the roof of a four-story building; connected to 
same was a 2-inch pipe running down the rear 
of the building with a connection left at the 
first floor for connecting the diflferent traps; 
above the said connection a quick opening 
valve was placed and below the connection the 
pipe was continued down about 10 or 12 feet. 
The water from the barrel was given a good 
start down the pipe and then the valve was 
closed quickly, and no unvented trap could 
stand the test." 

The Elmira plimibing code now recognizes 
separate back-venting for all fixture traps only, 
except in unusual instances. 

irUkesbarre, Pa, Anti-siphon trap tests 
were made for this city and witnessed by T. 
N. Thomson, consulting engineer, Scranton, 
Pa., and chief of the staff of instructors in 
plumbing of the International Correspondence 
Schools at Scranton. In these tests Mr. Thom- 
son states: "The trap was first connected into 
the side of a vertical waste pipe open at top 
and bottom. In this erection the trap was sub- 
jected only to siphonic action and performed 
its function well. But when an elbow was 
screwed on the base of the stack and several 
feet of horizontal waste pipe were added, this 
small addition was enough to reverse the test 
from siphonic to compression. The falling 
water entirely filled the horizontal waste line 
at base of stack, thereby preventing the com- 
pressed air from escaping at the water outlet. 
It therefore forced the water seal of the anti- 
siphon trap then under test, and blew a spray 
high in the air of the room. The results so 
caused precluded, I believe, the adoption of 
the anti-siphon traps by the city." 

Scranton, Pa. International Correspondence 
School. T. N. Thomson reports that he ob- 
served that, during heavy rainfalls, when the 
house sewer was running practically full and 
the fresh air inlet thereby closed, the air, 
which was sucked into the leader and forcibly 
driven down by the falling water column, 
forced its way into the house, when the traps 
were not thoroughly ventilated. 

Rochester, N. Y. While I endeavored to 
obtain the required information about the 
Rochester trap tests direct by correspondence, 
I failed to do so. It was therefore necessary 
for me to seek it elsewhere, and I was fortu- 
nate in obtaining it from Albert Webster, 
C.E., of New York City. Mr. Webster per- 



mitted me to copy the complete information 
about the Rochester tests from two blueprints 
which had been furnished him, I understand, 
direct by the Rochester Examining Board, and 
which I also understand to be authentic and 
official test records. From these blueprints I 
gather the following information: 

In 1908 the Examining Board of Plumbers 
of the City of Rochester, N. Y., which at that 
time consisted of Frederick E. Fladd, presi- 
dent; Thomas A. Morgan; Joseph F. Mon- 
aghan; Edwin A. Fisher, city engineer, ex- 
officio member; Frank DuMond, chief inspec- 
tor of plumbing, and J. Alfred O'Kane, clerk, 
conducted a series of siphonage tests on anti- 
siphon traps. The apparatus consisted of a 
50-gallon tank, 10 feet above a cut-off in a 
1^-inch iron pipe; 2 feet below this cut-off 
the traps were attached, and from the trap 
down to the drain was 35 feet. The tests were 
"5 seconds each alternating." The "velocity 
of water was 18 feet per second." The results 
of the tests are shown in Table A. 

In 1913 the Examining Board of Plumbers 
of the City of Rochester conducted another 
series of tests on other anti-siphon traps with 
an apparatus quite similar to that described 
above, except that the distance from the tank 
to the quick-opening gate valve is recorded 
as 8 feet 9 inches and from the latter to the 
drain as 32 feet. The record shows that the 
l^^-inch pipe discharged into a vertical 4-inch 
drain connection and that the trap connection 
was made to the side of the stack by means of 
a Y branch and 45-degree elbow. The results 
of the tests are shown in Table B. 

In connection with these Rochester tests, I 
desire to direct attention especially to the 
recorded velocity of flow, namely, 18 feet per 
second, which is equivalent to a rate of dis- 
charge of about 99 gallons per minute. 

I point out this most important fact for the 
reason that in my tests at 366 W. Broadway, 
New York City, as will be hereafter shown, 
the l^^-inch Cody (Geco) trap, which in the 
Rochester tests retained a 1-inch seal, was 
completely and ■ permanently siphoned under 
practically the same rate of flow, namely about 
75 gallons per minute. Furthermore, in our 
tests, this trap was connected to a 3-inch 
waste stack instead of a ll^-inch, and the 3- 
inch was wide open at the top, whereas the 
top of the 1%-inch Rochester stack was closed 
by its direct connection into the bottom of the 
tank and the quick-closing gate valve. This 



14 



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15 



means, while our conditions were apparently 
much less severe than those at Rochester, the 
Geco trap failed under our tests, while it re- 
tained a 1-inch seal under the apparently 
more severe Rochester tests. 

Holyoke, Mass. These tests are reported 
by F. L. Avery, inspector of plumbing, to have 
been made in 1903 to 1905 as follows: 

"An 80-gallon tank with quick-opening valve 
was installed with 1%-inch pipe and 60 feet 
drop as per sketch. This test resulted in the 
siphonage of all the traps, but while the water 
seal was lowered, several of the traps retained 
a seal from %-inch to 1%-inch, and repeated 
tfests failed to lower the seals. 

"Later a 90-degree ell was placed at the bot- 
tom of the riser with a length of pipe (about 
18 feet) installed with a pitch of %-inch per 
foot. The back pressure in lower trap was 
very pronounced, but trap still retained a par- 
tial seal even after repeated tests. 

"Again a test was made, the top of stack was 
extended about 6 feet and left open, and four 
sinks were installed to traps as per sketch. 
Paper was put over strainers and all sinks 
filled to top and let off at proper times. After 
repeated tests there was no appreciable lower- 
ing of the seals of the non-siphon traps ap- 
proved by this department.'* 

The sketch referred to by Mr. Avery shows 
that in the first series of tests, the 1 %-inch 
pipe was a straight vertical line without offset, 
connected at its top into the bottom of the 80- 
gallon tank. No measurements are given on 
the sketch to indicate the distances of the 
quick-opening valve and the trap from each 
other or from the tank. 

In the third series of tests the sketch shows 
the four sink branch wastes to have been 
spaced 15 feet apart, but does not indicate 
the exact location of the quick-opening valve 
and the upper branch waste, with reference to 
the tank bottom, nor that of the lowest sink 
waste branch with reference to the 90-degree 
elbow at the foot of the stack. 

No information was given to show the rate 
of flushing employed during the tests. 

While back pressure was developed in some 
of the tests, to a "very pronounced'* degree, 
the serious danger of such occurrences does 
not seem to have made a deep impression on 
those who witnessed the tests, judging from 
Mr. Avery's report. It has been so definitely 
proven that bacteria are carried in atomized 
sewage, such as occurs in the blowing of traps, 



that it should be by no means disregarded or 
slighted. There is a question whether the 
sewage blowing back into a fixture, such as a 
lavatory or a sink, or into a room through a 
water closet, may not contain small amounts 
at least of the discharges from the fixtures 
above, which might well, carry fecal matter or 
urine, if these fixtures happen to be water 
closets or urinals. 

It is unfortunate that the Holyoke tests, 
similar to those in Rochester and elsewhere, 
were made with a 1%-inch pipe stack which, 
at least according to the New York City 
plumbing code, is not used in actual practice. 
The absence of any information on the rates 
of flushing and the lengths of flushing periods 
makes it practically impossible to express any 
real opinion on the value of the siphonage 
tests. 

Springfield, Mass. The tests were made 
under the supervision of Frank W. Tower, 
chief plumbing inspector, from 1897 to 1914, 
inclusive. Mr. Tower gives the following 
information: 

The tests were limited to siphonage resist- 
ance and no tests were applied to determine 
resistance to back pressure. Traps were at- 
tached to a branch of a vertical 1%-inch pipe 
connected at its top into the bottom of a flush 
tank, and tested under a 30-foot fall with 
three successive 12-second pulls of the tank 
valve, without refilling traps. 

The trap waste branch was formed by a 
threaded T-Y drainage fitting which was 
located about 6 inches below the tank valve. 
The latter was placed 18 inches below the 
bottom of the. tank. The actual distance from 
the branch waste connection to the foot of the 
stack was 29 feet 8 inches; the tank had a 
capacity of 17% gallons and was discharged 
at a rate of about 75 gallons per minute. The 
tank valve was a 1%-inch wheel compression 
type valve. 

The records supplied by Mr. Tower show 
the following results of seal left in traps after 
three flushes: Wolverine, 14/16-inch; Sanitas, 
13/16-inch; Dome or Drum, 12/16-inch; Con- 
nolly, 12/16-inch; Femco, 12/16-inch; New- 
ton, 11/16-inch; McAuliffe, 10/16-inch; Posi- 
tive, 10/16-inch; Imco, 10/16-inch; Hajoca, 
No. 10, 10/16; Monarch, 10/16-inch; Para- 
gon, 8/16-inch; Radcliffe, 8/16-inch; Bowers, 
2/16-inch; Cudell, 0; Clean Sweep, 0; King, 
0; Centrifugal, 0. 

In general the Rochester and Springfield 



16 



PLUMBING FIXTURE TRAPS 



tests were fairly similar, except that the 
Rochester distances from tank to valve, from 
valve to trap branch, and from trap branch to 
foot of stack were greater, that the Springfield 
flushes were of 12 seconds duration and 75 
gallons per minute rate against 5 seconds 
duration and about 100 gallons rate in 
Rochester. 

Neither the Rochester nor the Springfield 
tests were made under conditions which are 
in any way similar to those existing in actual 
plumbing systems. Aside from the all-impor- 
tant fact that they were made on clean, in- 
stead of fouled traps, the use of an 1^-inch 
vertical waste stack, closed at its top, intro- 
duces conditions which do not exist in good 
plumbing practice. 

Therefore it does not appear to me that 
any value whatever attaches to the tests, ex- 
cept only that of determining, the relative 
siphonage resisting qualities of anti-siphon 
traps, when compared with each other, but 
not that of determining the value of unvented 
anti-siphon traps under actual conditions of 
use. 

It is of special interest to note as reported 
to me by Mr. Tower, that since 1917 the use 
of seven of the thirteen previously approved 
anti-siphon traps, namely, the Connolly, New- 
ton, Sanitas, McAuliffe, Positive, Radcliffe 
and Femco has been discontinued, and that 
the traps now approved are the Dome or 
Drum, Imco, Wolverine, Hajoca No. 10, Mon- 
arch and Paragon. It appears therefore that 
the tendency in Springfield is to gradually 
abolish the use of unvented anti-siphon traps. 
Bridgeport, Conn. During the recent war 
the U. S. Housing Corporation installed in 
some of its developments plumbing systems 
with unvented traps of a type similar to the 
old-fashioned Drum or Bottle trap. Among 
these developments the most notable were the 
apartment buildings of the "Black Rock" and 
the "Mill Green" groups at Bridgeport, Conn. 
In view of doubts cast by the city of Bridge- 
port on the safety of plumbing work contain- 
ing these unvented traps, a committee was 
appointed in 1919 by the U. S. Housing Cor- 
poration and, I understand, was liberally paid 
by it to undertake an investigation and cer- 
tain tests of, and make a preliminary report 
on the quality and character of plumbing 
work as designed and installed by its own 
clients, who had consistently defended it there- 
tofore. A final report was never rendered to 



my knowledge, for the committee realized 
that such final report could not be made 
in view of the fact that its work had not been 
completed; indeed, it recommended that addi- 
tional tests and experiments should be made, 
which, however, it has, unfortunately, never 
been authorized to make. The buildings are 
now occupied and it is highly improbable that 
this important investigation, which might have 
been most valuable, will ever be carried to a 
conclusion. 

The city of Bridgeport was forced, I under- 
stand, by threat of a law suit to allow the 
plumbing systems to remain, on the ground of 
a technicality in the wording of its original 
formal permit, which was intended to be lim- 
ited to the war emergency duration, but was 
by a fluke left open for an unlimited period. 

It would be futile to attempt in this report 
a description of incompleted tests. Suffice it 
to say that the committee, consisting of Albert 
L. Webster, consulting engineer. New York 
City, chairman; Dr. Wm. Paul Gerhard, con- 
sulting engineer. New York City, secretary; 
Chas. S. Ball, chief inspector. Division of Sani- 
tation, Department of Health, Chicago; Nel- 
son S. Thompson, chief mechanical engineer. 
Supervising Architect's Office, Washington, 
D. C, and J. W. McCarthy, plumbing con- 
tractor, Washington, D. C, prepared, at the 
request of its clients, a preliminary report 
which was so thoroughly limited by qualifica- 
tions and restrictions, and in addition thereto 
recommended the need of further tests and 
experiments, that no broad conclusions can 
be drawn therefrom on the merits or weak- 
nesses of unvented anti-siphon traps. Neither 
do I believe from conversations held with the 
chairman of the committee, that he would 
underwrite any conclusions of this kind. 

Existing Conditions in Cities of the United 
States. — Before proceeding to the tests made in 
New York City, during 1918-1919, which are 
so intimately connected with our own investi- 
gations, it would seem proper and pertinent 
to review briefly the present conditions in 
other cities of this country with regard to 
the general use of unvented anti-siphon and 
vented bent tube or ^/4-S traps. To this end I 
vn-ote to the chief plumbing inspectors of 
those cities in this country outside of New 
York City, which were recorded in the "Stan- 
dard Diary" of 1919 as having in 1916 an esti- 
mated population of over 35,000 inhabitants; 
there were 185 such cities listed. A total of 



PLUMBING FIXTURE TRAPS 



17 



107 replies were received to the inquiries, most 
of which were accompanied by a copy of the 
plumbing code. 

Tabulations shown in Table C have been 
prepared from the material gathered in this 
manner. 

It must be freely admitted that the tables 
fail to show the conditions in the seventy- 
eight following cities, to whose chief plumbing 
inspectors inquiries were also sent, but from 
whom no replies or plumbing codes were re- 
ceived : 

Amsterdam, N. Y.; Atlantic City, N. J.; 
Augusta, Ga. ; Baltimore, Md.; Binghamton, 
N. Y.; Boston, Mass.; Buffalo, N. Y.; Butte, 
Mont.; Camden, N. J.; Charleston, S. C. ; 
Charlotte, N. C; Chattanooga, Tenn.; Chester, 
Pa.; Dallas, Tex.; Dubuque, la.; East Orange, 
N. J.; El Paso, Tex.; Erie, Pa.; Evansville, 
Ind.; Everett, Wash.; Fall River, Mass.; Fitch- 
burg, Mass.; Fort Worth, Tex.; Grand Rapids, 
Mich.; Hamilton, Ohio; Harrisburg, Pa.; 
Haverill, Mass.; Hoboken, N. J.; Huntington, 
W. Va.; Jackson, Mich.; Joliet, 111.; Kala- 
mazoo, Mich.; Knoxville, Tenn.; Lancaster, 
Pa.; Lansing, Mich.; Lexington, Ky. ; Man- 
chester, N. H.; McKeesport, Pa.; Mobile, 
Ala.; Mt. Vernon, N. Y.; New Castle, Pa.; 
New Rochelle, N. Y. ; Norfolk, Va. ; Oklahoma 
City, Okla. ; Oshkosh, Wis.; Passaic, N. J.; 
Pawtucket, R. I.; Peoria, 111.; Perth Amboy, 
N. J.; Portland, Me.; Portsmouth, Va.; Provi- 
dence, R. I.; Reading, Pa.; Roanoke, Va. ; 
Sacramento, CaL; Saginaw, Mich.; St. Joseph, 
Mo.; St. Paul, Minn.; Scranton, Pa.; Sioux 
City, la. ; Somerville, Mass. ; South Bend, Ind. ; 
Springfield, 111.; Springfield, Ohio; Superior, 
Wis.; Syracuse, N. Y.; Taunton, Mass.; 
Topeka, Kan.; Troy, N. Y. ; West Hoboken, 
N. J.; Wheeling, W. Va.; Wilkes-Barre, Pa.; 
Wilmington, Del.; Yonkers, N. Y.; York, Pa.; 
Youngstown, Ohio. 

The total population of the cities to which 
inquiries were sent, as given by the 1916 cen- 
sus estimates and the replies was approxi- 
mately 29,900,000; that of the cities answering 
the inquiries, 22,963,000. Therefore, while 
authentic information is available from only 
about 58 per cent of the total cities, it covers 
about 77 per cent of their population. 

An analysis of the returns shows the fol- 
lowing facts: 

1. In 81 per cent of the number, and in 84 
per cent of the population of the cities, un- 
vented anti-siphon traps are not permitted for 



general use in new buildings. 

2. In about 40 per cent of this number and 
about 24 per cent of this population, anti- 
siphon traps are not allowed, whether vented 
or unvented, for general use in new buildings. 

3. In about 4 per cent of the number, and 
in about 4 per cenr of the population of the 
cities from which information is available, 
are unvented anti-siphon traps permitted for 
general use, but with decided limitations. 

4. In about 17 per cent of the number, and 
in about II per cent of the population of the 
cities, is the general use of unvented anti- 
siphon traps permitted. 

5. In these cities, in which unvented anti- 
siphon traps are permitted, the maximum al- 
lowable distances from the traps to the soil or 
waste stacks varies from 18 inches to 25 feet; 
in the case of Macon, Ga., there is no extreme 
limit. 

6. In not a single city, except New York, 
is only one anti-siphon trap reported approved 
to the exclusion of all others. 

7. In not a single city is the 1% inch to 
2 inch Geco trap approved by the Board of 
Standards and Appeals of New York City, re- 
ported as approved or in use. 

Opinions of Plumbing Officials of Other 
Cities About the '^Geco Trap." — Since the 
reports show that the "Geco" trap has not 
been approved by any other city in this coun- 
try, I had an accurate actual size sectional 
drawing prepared in my office and had blue- 
prints sent to the chief plumbing inspectors 
of those cities in which the reports showed 
the use of anti-siphon traps, whether vented 
or unvented, permissible. It was my purpose 
to ascertain, if possible, the opinions of these 
officials about the design of this trap. 

A blueprint like those forwarded to the city 
officials is shown in this connection. To their 
inquiries I received the following replies, all 
of which are herewith transmitted with the 
permission of their writers: 

1. R. E. Nelson, Salt Lake City, Utah: 
"Our code requires all traps to be vented 
either on the crown or in the rough, but your 
trap may be used when vent pipes cannot be 
installed." 

2. Inspector of plumbing, Holyoke, Mass., 
name withheld by request: "The writer is of 
the opinion that this trap would retain a water 
seal under any conditions to be met with in 
ordinary plumbing. The principles of the re- 
duced inlet with slightly enlarged outlet, the 



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1 Anti-Siphon Traps for General, But Not Limited Use in New Work. 






PLUMBING FIXTURE TRAPS 



10 



partitions acting as baffle or retarding rings 
and the enlarged bowl allows for a great dis- 
placement of water with large refill, and while 
under severe conditions the seal of trap would 
be lowered, I am of the opinion that with the 
refill there would always be a partial seal of 
sufficient depth to retard all sewer air. 

"There might be an objection that this trap 
would easily stop up at partition near the inlet 
end, but with the submerged cleanout directly 
under, it is easily cleaned and has the advan- 
tage of keeping the stoppage in trap rather 
than some inaccessible point." 

3. Thos. M. Landers, chief plumbing inspec- 
tor, Richmond, Va.: "I will say that I am 
familiar with the characteristics or principles 
in the print of the trap that you sent me, for 
it is either the Sanito trap, made by The J. L. 
Mott Co., New York City, or its duplicate. I 
must say it is a very excellent trap and has 
given entire satisfaction." 

4. Inspector of plumbing, Bay City, Mich., 
name withheld by request: "I certainly would 
allow such a trap to be used for kitchen 
sinks, for I think it is as safe as any trap we 
are using." 

5i A. W. Young, plumbing inspector, Oma- 
ha, Neb.: "On old work where it is impos- 
sible to vent, we permit the use of anti-siphon 
traps, if they are approved by this department. 
The design of trap you submit would be per- 
mitted to be used where anti-siphon traps have 
to be used." 

6. E. F. LaForce, inspector of plumbing, 
Schenectady, N. Y.: "We have rejected several 
traps because the inlet, outlet or cleanouts 
are too small, and this trap seems to have sev- 
eral of these faults." 

7. Plumbing inspector, St. Louis, Mo., name 
withheld by request: "I am not willing to ap- 
prove same for general use in plumbing work." 

8. Thos. J. ClaflFy, assistant sanitary inspec- 
tor, Chicago, 111.: "This trap has been given 
some consideration in the past by this office, 
and we are convinced that it is much like other 
anti-siphon traps in that it has some re-sealing 
features, but is not proof against back pres- 
sure in an unvented plumbing system. 

"We are convinced also that it can be si- 
phoned so as to lose nearly all of its seal, but 
aside from that, we believe that it is open to 
more serious objections. The body of the trap 
is so enlarged that the course of the stream of 
water flowing through it is broken, the speed 
of the stream slowed up considerably, and the 



scouring action which obtains in the ordinary 
half S or P trap is almost entirely lost. 

"Experience teaches us that if this trap were 
used generally under sinks and similar plumb- 
ing fixtures through which greasy wastes are 
discharged, that in a comparatively short time 
the waterway through the body of the trap 
would become so filled with grease as to reduce 
the bore to the same size as the smallest open- 
ing into the trap, which would be approximate- 
ly 1-inch. We would then have nothing but a 
long P trap without any of the re-sealing or 
anti-siphon qualities claimed, and with a large 
body of foul, greasy, putrid wastes on the 
interior. Such traps as this will not be ap- 
proved in this city. 

"The tendency now in sanitary engineering 
and plumbing practice is to get away from the 
more complicated forms of traps with their 
long water travel and irregularities and to 
stick to the simple, straight, smooth bore P 
or % S trap which has the easiest waterway, 
the smoothest flow and the greatest scouring 
action." 

9. W. T. Galloway, supervisor of plumbing, 
Kansas City, Mo. : "Not willing to approve trap 
for general use, unless same is to be vented." 

10. Wm. J. Jackley, chief inspector of 
plumbing, Dayton, Ohio: "It would have to be 
back-aired or vented." 

11. J. J. Kimley, inspector of plumbing, 
Quincy, Mass.: "I cannot allow the use of it 
without a back vent." 

12. Peter P. Griffin, plumbing inspector, 
Salem, Mass.: "The writer wiU have to with- 
hold further endorsement." 

13. A. R. McGonegal, inspector of plumb- 
ing, Washington, D. C: "I believe it good 
practice to require that in every conceivable 
condition of service a trap shall maintain a 
safe seal, that it shaU not have any cast par- 
tition between any two parts of the trap which 
may in even remote possibility have a sand 
hole, shrinkage crack or split capable of leak- 
age of gas or water in such manner that the 
efficiency of the seal can by any manner be 
destroyed or even seriously affected; auJ that 
it shall have no deflector capable of so direct- 
ing the flow of waste that there is any possi- 
bility of any of it falling or being directed 
back into the stream of waste. 

"This office would not approve a trap con- 
structed as per blueprint, even though it main- 
tained a seal, on account of the features of ca?t 
partition and deflector mentioned above. This 



20 



PLUMBING FIXTURE TRAPS 



letter is not only my official opinion, but my 
personal one also.** 

14. Edgar E. Kroul, inspector of lilumbing, 
Elmira, N. Y.: "I would not approve of any 
trap containing the features as shown on the 
above-mentioned blueprint. The trap on the 
blueprint has too great an amount of watjr 
and depth of seal to be self-scouring despite its 
contour, except under a greater pressure than 
would actually occur in ordinary usage, and 
no trap with an 1%-inch outlet should have 
passages cut down to 1-inch." 

15. F. W. Cloutier, chief plumbing inspec- 
tor, Minneapolis, Minn.: "I would not approve 
for use in this city an anti-siphon trap such as 
shown in the blueprint, as I do not consider it 
designed along practical lines." 

16. Adolph Anderson, building inspector, 
Duluth, Minn.: "Our ordinance provides for a 
certain minimum size waste pipe from fixtures. 
A trap is part of such waste pipe and it follows 
from a legal point of view that the minimum 
area of these passages should not be smaller 
than minimum size of waste pipes allowed. 
Furthermore, our building code provides that 
all plumbing fixture traps must be properly 
vented. Therefore, we must rule that these 
traps when no provisions are made for venting 
same, are not allowed in this city." 

17. John Campbell, plumbing inspector, 
Paterson, N. J.: "We would beg to be excused 
at this time from making any comment on the 
construction of this type of anti-siphon trap, 
cither favorable or unfavorable, for the reason 
that we have not seen its operation for any 
length of time in general use." 

18. J. F. Dowd, chief sanitary inspector, 
Cincinnati, Ohio: "Permit me to say that we 
would not allow the use of this trap in our 
city for several reasons: 

"First. The inlet side of the trap must be 
the same as the outlet. 

"Second. Partition at *A* would not be per- 
mitted. 

"Third. Partition at *B' would not be per- 
mitted, as our law does not permit the use of 
partitions in traps. 

"Fourth. *C* would have to be at least 1%- 
inch opening. 

"Fifth. 'D' would also have to be a 1%-inch 
opening; in other words, our code does not 
permit the trap to be decreased in any part of 
the bore; it must be the same bore as the out- 
let side of the trap." 

19. John F. Smith, plumbing inspector, 



Jamestown, N. Y.: "We do not use anything 
but the centrifugal action pattern." 

20. F. W. Connolly, chief plumbing inspec- 
tor, Rochester, N. Y.: "The Board does not ap- 
prove of traps having partitions." 

21. Winfield S. Reed, supervisor of house 
drainage, Philadelphia, Pa.: "1 beg to say that 
I am personally opposed to any trap that ha& 
any restriction in the interior of the appliance. 

"The obvious intent and purpose of a waste 
connection is to remove sewage. It is unques- 
tionably good practice to remove it from the 
fixtures as rapidly as possible. With this end 



IX' IRON PIPE 
THREAD 




CtEANOUT 



Cross Sectional Diagram of the **Geco* 
Siphon Trap 



Anti' 



in view, certain size of pipes are designated 
and required specifically for the fixture to be 
drained. I am therefore of the opinion that it 
would be decidedly inconsistent to designate 
the size of a waste pipe 1%-inch in diameter 
and a trap of similar size, and then restrict 
the area of the interior at certain points, whicb 
no doubt would have a retarding influence on 
the discharge. Again 1 question the effect it 
would have on the scouring of the trap, which 
occurs in a trap of uniform diameter. 

"In view of the foregoing, therefore, I should 
not approve of the use of the trap referred to." 

22. Chas. A. Rainger, chief inspector of 
plumbing, Cleveland, Ohio: "This trap posi- 
tively would not be allowed in Cleveland, as it 



PLUMBING FIXTURE TRAPS 



21 



conflicts with several sections of our code; one 
being that there is a material reduction of the 
pipe area in the direction of the flow and an- 
other being that the cleanout must be same size 
as the largest area of the trap. I also note in 
the construction of the trap that it has what 
we would term a concealed interior partition, 
which in case of defect, would greatly reduce 
the seal. 

"I do not believe that this trap has many 
good features to recommend it, and certainly 
not any that would commend it as a proper 
fixture trap to install without proper venting.*' 

23. Chas. A. Hallgring, chief plumbing in- 
spector, Newark, N. J.: "We do not approve of 
any trap which is less than W2 inches in 
diameter. 

"Traps with interior chamber or mechanism 
are prohibited. The trap which you show with 
its reduced diameter and baffle partition I 
would consider a violation of our code and 
would not approve its use." 

24. Arthur C. Shaver, inspector of plumbing, 
Pasadena, Cal.: "Personally I would not ap- 
prove the New York pattern for general use 



in plumbing work without taking the same pre- 
cautions that would be necessary with an ordi- 
nary % S trap. Partition is more or less an un- 
known quantity. With a concealed partition 
of this kind there is always the possibility of a 
poor casting, and a whole or a part of the par- 
tition omitted. The centrifugal motion of the 
water in the trap, caused by partitions A and 
B, will cause lint, string, hair and other foreign 
substances to be rolled into a ball, and in time 
close the trap entirely. I have seen this happen 
many times when the so-called centrifugal trap 
was used in connection with the laundry tray 
or lavatory. When the New York trap is new 
and clean it will withstand siphonic action, or 
re-seal itself under ordinary conditions, but in 
my opinion with continuous use, the trap will 
foul and have no more siphonic qualities than 
the ordinary % S trap." 

25. Thomas N. Thomson, consulting engi- 
neer, Scranton, Pa., and former director of 
plumbing course, International Correspondence 
School: "The projecting partition A being con- 
cealed, is of a character that is subject to sus- 
picion. It may be cast with a blow-hole 



Cities Which Would Permit the Geco Trap 
Without Venting for General Use 
Name Population 

Holyoke, Mass 72,000 

Richmond, Va .163,000 

Bay City, Mich 45,000 

Total 280,000 



Cities Which Would Permit the Geco Trap 
Without Venting for Emergency Only 
Name Population 

Salt Lake City, Utah 150,000 

Omaha, Neb 280,000 

Total 430,000 



Cities Which Would Permit the Geco Trap 
with Venting Only 
Name Population 

Springfield, Mass 130,000 

Kansas City, Mo 400,000 

Dayton, Ohio 175,000 

Quincy, Mass 55,000 

Duluth, Minn 110.000 

Pasadena, Cal 60,000 



Total 930 000 



Cities Which Would Not Permit The Geco 
Trap, Whether Vented or Not 
Name Population 

Schenectady, N. Y 100,000 

St. Louis, Mo. 850,000 

Chicago, 111 2,750,000 

Washington, D. C ". 365,000 

Elmira, N. Y 50,000 

Minneapolis, Minn ' 400,000 

Cincinnati, Ohio 450,000 

Jamestown, N. Y 46,000 

Rochester, N. Y 250,000 

Philadelphia, Pa 2,000,000 

Cleveland, Ohio 900,000 

Newark, N. J 450,000 

Total 8,611,000 



Table D.^Summary of Opinions of Several Plumbing Inspectors Relative to the ^^Geco** Trap 



22 



PLUMBING FIXTURE TRAPS 



through it, which might short-circuit the re- 
mainder of the trap seal. 

"Restrictions in waste pipes and other chan- 
nels employed in the conveyance of sewage, are 
detrimental inasmuch as they tend to hold back 
the sewage and catch and hold the larger solids 
which accompany the water. 

"The reduction of the opening at C, I con- 
sider a special disadvantage, as it causes a 
higher velocity at the overflow which, in an 
unventilated anti-siphon trap, tends the more 
to lift water out of the trap along with the air. 
For general use I consider the inlet and outlet 
apertures too small. They should be full size 
of the pipe. 

"I also consider the bag too low. There is a 
considerable quantity of useless water and foul- 
ing surface below the level of the tongue. This 
water has no re-sealing value." 

26. Springfield, Mass., name withheld by re- 
quest: "I see no reason why such a trap could 
not be installed for general use with suitable 
ventilation." 

A study of these statements on the value of 
the "Geco" trap by men who know from train- 
ing and experience, who have no interest in 
this trap to any greater or lesser degree than 
in any other non-siphon trap, by men whom 
any fair-minded person will, I think, consider 
unprejudiced, shows that the great preponder- 
ance of opinion is adverse to the general use 
of the trap with or without venting; that is, 
the trap per se, as will be seen from the tabu- 
lation given in Table D. 

These tables show the competent officials of 
only three cities with a total population of 
280,000 as apparently not opposed to the Geco 
trap for general use without venting ; of only 
two cities with a total population of 430,000 
as apparently not opposed to the Geco trap 
for emergency use without venting; of six 
cities with a total population of 930,000 as not 
opposed to the general use of the Geco trap 
with venting, and of twelve cities with a total 
population of over eight and a half million as 
opposed to the use of the Geco trap, whether 
vented or unvented. Among the latter are 
"Washington, D. C., Chicago, 111., St. Louis, 
Mo., Philadelphia, Pa., and Cleveland, Ohio. 

In addition thereto we find Rochester and 
Schenectady, N. Y., both of which do permit 
the general use of unvented anti-siphon traps, 
and Cincinnati, Ohio, which permits a lim- 
ited use of anti-siphon traps, as opposed to the 
Geco trap with or without vent; we find 



Springfield, Mass., which has tested and ap- 
proved numerous anti-siphon traps without 
vents as opposed to the use of the Geco trap 
unless properly vented. 

Such evidence as this cannot be questioned. 
Professor Charles F. Chandler, dean of 
Columbia University, in speaking of the pres- 
ent attempt to adopt "a patent trap" in New 
York City, stated in public at the Cheihists' 
Club of New York, on January 16, 1920, on 
the occasion of the presentation of the Per- 
kins Medal to him for notable achievements. 
"To adopt this would be a crime." 

With the kind permission of my readers, I 
would like to dwell a few moments longer on 
the subject of the "Geco" trap, by giving my 
own ideas on its design. 

The appearance of the nickel-plated trap 
from the outside is rather pleasant and 
unobjectionable, although somewhat bulky 
perhaps. 

True, it. seems to impress one with its ab- 
sence of corners, its smoothness of finish, and 
its gradual curves suggesting innate cleanness. 

But when bi-sected and its inner self is laid 
bare, the story is different. Instead of highly 
polished and plated smooth surfaces which 
would reject filth, we see rough brass, con- 
taining minute depressions, and projections 
and unevenly cast faces which, unlike the 
smooth, bent, brass tubes of the %-S trap, 
afford innumerable splendid lodging places 
for the commencement of grease and filth de- 
position with subsequent ever increasing 
rapidity of accumulation. 

We see two cleverly concealed partitions, 
one at the inlet and the other at the outlet end, 
although the revised New York City plumbing 
code, effective January 27, 1919, prohibits 
traps "that depend upon interior partitions for 
a seal." 

It is plainly evident that the lower 1^-inch 
of the trap seal is entirely dependent on the 
partition at the inlet end. In view of the 
results of the "official" tests of the trap at No. 
30 City Hall Place by the New York City 
Board of Standards and Appeals, which re- 
duced the trap seal by siphonage to about % 
inch, this is a very serious matter. 

Cracks and sand holes occur frequently in 
castings of all kinds and, when present in the 
partition, cannot be detected; partitions also 
are subject to penetration by corrosion. With 
a trap seal lowered as in the tests to %-inch, 



PLUMBING FIXTURE TRAPS 



23 



any cracks, sandholes or perforations in the 
lower partition will vitiate the trap. 

It is not clear to me, therefore, how the 
Board of Standards and Appeals can consist- 
ently approve a trap which violates the plumb- 
ing code prepared by the same board. 

It is also seen from an inspection of the 
dissected 1%-inch "Geco" trap that its inlet 
opening is contracted at the top to 1%-inch, 
and at the bottom in one diameter to 15/16- 
inch, and at right angles thereto to 1%-inch; 
its outlet opening to 1 1/32-inch and 1%- 
inch, respectively. At these restrictions the 
cross sections are oval. The areas of cross 
sections are as given in Table E., page 27. 

Hence the restricted areas, expressed in per- 
centage of the full 1%-inch bore outlet area, 
are as follows : 

Inlet at top, 70% 
Inlet at bottom, 57% 
Outlet, 63% 

The restricted minimum diameters, expressed 
in percentage of the full 1%-inch outlet 
diameter, are as foUows; 

Inlet at top, 83% 
Inlet at bottom, 63% 
Outlet 69% 



That framers of the N. Y. C. plumbing code 
did not propose to have any waste pipe dia- 
meters and trap sizes smaller than 1%-inch, 
is shown in paragraphs 90 and 112. Hence 
the "Geco" trap conflicts with the code. 
Personally, I object seriously to, and I would 
not specify any trap having any passage 
80 decidedly restricted in any diameter or 
area. Pins, broken matches or toothpicks, 
broom straws and similar substances would 
easily pass through the fixture strainer and 
become lodged crosswise at the restricted diam- 
eter, producing thereby the initial foundation 
for complete stoppage. 

I have to state also that, when the trap 
contains sediment and has its contents vio- 
lently disturbed by a discharge of water from 
a fixture above through its soil or waste stack, 
h has the tendency to throw back the sedi- 
ment from the underside of the outlet end par- 
tition into the restricted inlet and thereby 
dogs the latter. This was demonstrated at 



the "official" test made at No. 30 Qty Hall 
Place. 

At the conclusion of this test I had the 
cleanout screw removed and attempted to 
insert my little finger into the restricted inlet 
opening. This I was unable to do, since this 
opening was practically closed with tightly 
packed sediment, such as sand, sawdust, tea 
leaves and cofifee grounds, with which the trap 
had apparently been tested for self-cleaning, 
and a part of which remained in the trap. 

A comparison of the "Geco" trap with the 
ordinary % S trap re. their relative self -clean- 
ing properties is of considerable interest. The 
formation of an opinion on the relative amount 
of settleable solids which wiU be deposited in 
any two chambers of unequal design requires 
consideration mainly of the following con- 
ditions : 

1. Character of the liquid passing through. 

2. Degree of surface roughness of the 
chambers. 

3. Nimiber of changes in direction of flow 
and radius of curvature of same. 

4. Number and design of baffles or projec- 
tions tending to retard the flow. 

5. Maximum cross section area of flow. 

6. Velocity of flow. 

7. In the case of liquids containing colloi- 
dal, congealing or sticky . substances, the ratio 
of the cubical contents to the wetted surfaces. 

In the case of plumbing traps the character 
of the liquid depends mainly on the use of the 
individual fixture to which the trap is attached. 
Outside of water closets there are probably no 
fixtures from which liquids are discharged 
which contain a greater amount of settleable 
solids than kitchen sinks. In addition to the 
settleable solids, such as coffee grounds, tea 
leaves, food remnants and undissolved soap 
particles, the sink wastes contain frequently 
considerable amounts of grease and sticky 
substances from pots and kettles. 

Much of the suspended matter in sink dis- 
charges is not settleable, but so finely divided 
that it refuses to settle and is in the form 
called "colloidal." It is well known that such 
colloids, which do not settle of their own voli- 
tion, are electrically charged and will attach 
themselves by electro-magnetic force to any 
surfaces at rest, near which they happen to 
float. The greater such surfaces, the greater 
will be the amount of colloids deposited. 

The surface area is not only dependent on 
the shape or design of a trap, but also on the 



24 



PLUMBING FIXTURE TRAPS 



degree of surface roughness. A smooth drawn 
brass surface, for instance, may have only 75 
per cent, of the actual area of a surface of 
rough cast brass of equal dimensions if all the 
minute crevices and projections of the latter 
v^ere measured. 

Moreover, the rough cast brass surfaces oflFer 
greater friction to the flow than do the smooth 
drawn brass surfaces, and thereby they tend 
to decrease the velocity of flow. That the 
deposition of solids increases with the reduc- 
tion of velocity of flow is well known; for this 
reason we provide for minimum slopes of waste 
and sewer pipes. 

The more changes in direction of flow, and 
the smaller their radius of curvature, the more 
will the velocity be retarded. Sharp corners, 
such as at the outlet baffle of the "Geco" trap 
are objectionable because of their very small 
radius of curvature. Still further, the baffle 
at the outlet end of this trap tends to reject 
the flow and will materially increase the dep- 
osition of solids. 

The velocity of flow is directly proportional 
to the cross section area. In the 1%-inch 
*'Geco" trap the maximum cross section area 
is an ellipse 4%-inchX3-l/16-inch=13.8 
square inches; in the ordinary V2 S trap the 
cross section area is* 1.76 square inches. 
Hence the minimum velocity of liquids pass- 
ing through the 1%-inch V2 S trap is nearly 
8 times as great as that passing through the 
1%-inch Geco trap. That such a marked dif- 
ference in velocities produces a decidedly 
marked difference in the amount of sedimen- 
tation, is self evident. 

The total capacity of the 1%-inch Geco 
trap is 49.6 cubic inches; that of the ordinary 
% S trap having a 2-inch seal is 9.60 cubic 
inches. The wetted area of the former is 76.4 
square inches, of the latter 32.5 square inches. 
During periods of quiescence of the trap water, 
grease contained in equal proportions in the 
water of both traps would be deposited on the 
surfaces of both traps; but the greater the 
amount of water the greater the amount of 



available grease, and the smaller the available 
area of deposit the greater will be the thick- 
ness of deposit. 

Hence, if the ratio of contents to wetted area 
in the Geco trap is 49.6-i-76,4=:,65 and of 
the P traps 9.6^32.5 =.3, it follows that the 
thickness of deposited grease in the Geco trap 
will, during the same rest periods, be .65-i- 
.3= about twice as great as in the P trap. 

Summing up briefly my opinion of the 1-^- 
inch Geco trap, I would say: 

1. The trap has a pleasing exterior. 

2. While its depth of seal is about double 
that of a good %-S trap, it is probably within 
the limit of requirements of a self-cleaning 
trap. 

3. Its lower partition is a violation of pro- 
vision 100 of the New York City Plumbing 
Rules and Regulations, as adopted by the 
superintendents of buildings, effective April 
23, 1912, and as amended by the Board of 
Standards and Appeals, July 5, 1917, and 
December 27, 1918; effective January 27, 1919. 

4. The three restrictions in its diameters, 
namely, at the top of the inlet tube, at the 
bottom of the inlet tube, and at the outlet tube, 
are violations of paragraphs 90 and 112 of the 
same rules. 

5. It offers greater resistance to the flow of 
liquids than the % S trap. It thereby de- 
creases the velocity and increases the fouling 
capacity. This greater resistance is caused by 
(a) rougher interior surfaces, (b) sharp turn 
at outlet partition which produces high fric- 
tion, eddies and counter-currents. 

6. Its minimum velocity of flow for the 
same rate is, on account of its large cross sec- 
tion area, only about Vs of that in a % S trap. 

7. Its rough interior surfaces will collect 
colloids considerably more rapidly than the 
smooth walls of the drawn tube P traps. 

8. The shape of the trap is such that under 
high rates of flow there will be circular eddies 
tending to wrap hair, lint and other fibrous 
materials into balls and to reject them, to- 
gether with other suspended substances, into 



Restricted inlet at top, 1.225 square inches= circle 1.25-inch diameter 

Restricted inlet at bottom, 1.012 square inches=circle 1.13-inch diameter 

Restricted outlet, 1.114 square inches=circle 1.19-inch diameter 

Full bore, 1.766 square inches=circle l;50-inch diameter 



Table E. — The Areas of Cross Sections of the Geco Trap 



PLUMBING FIXTURE TRAPS 



25 



the contracted inlet. That such reverse action 
of flow and consequent deposition of tightly 
packed solids does take place was proven by 
the previously recited condition of the trap 
after tests at 30 City Hall Place. 

9. During the same rest periods and with 
water containing the same percentage of 
grease, the thickness of grease congealed on 
the walls of the 1%-inch Geco trap wiU be 
theoretically twice as thick as that deposited 
on the walls of the 1^-inch P trap. 

10. Since the velocity of flow through the 
P trap is about 8 times as great as it is 
through the enlarged body of the Geco trap, 
the grease will be torn away from the walls of 
the former by the water while it remains in 
the latter. 

TESTS OF GECO TRAP MADE BY THE 

N. Y. CITY BOARD OF STANDARDS 
AND APPEALS. 

1. AT 30 CITY HALL PLACE. 

On August 13, 1918, the New York City 
Board of Standards and Appeals held a 
public hearing in its ofl&ce in the Munici- 
pal Building, New York City, on certain 
proposed changes in the plumbing code, the 
most vital of which would permit the in- 
stallation of unvented so-called anti-siphon 
traps, a substitute for the vented % S or S 
traps which had been in use in New York City 
for upward of 40 years, and had been found 
entirely satisfactory and as nearly perfect as 
any apparatus can be. 

The "Geco," also known as the "Cody" trap, 
is the only trap approved to date, about 2 
years after the initial hearing, although there 
are many other anti-siphon traps on the mar- 
ket which will compare favorably both as to 
resistance to siphonage and back pressure, 
and as to self-cleaning, with the one approved. 

It developed during the course of the hear- 
ing on August 13, 1918, that tests of the trap 
for siphonage resisting qualities had been 
made by the trap manufacturers in the pres- 
ence of representatives of the Board of Stand- 
ards and Appeals, but that no other interested 
parties, such as architects, engineers, builders, 
master or journeymen plumbers had witnessed 
these tesfs. 

A demand was made of the Board that a 
public test be held; at the suggestion of the 
chairman this was arranged and was con- 
ducted by the trap manufacturers, informally 



and in the absence of the Board, on the same 
date at 3 P. M., at 30 City Hall Place. 

The photograph on page 71 shows the 
general testing apparatus employed. It was 
erected on the rear fire escape and had no 
connection with the plumbing system; the 
water used in the tests was discharged on an 
adjoining roof. 

The apparatus consisted of a vertical 1%- 
inch iron screw pipe about 50 feet long, to the 
upper end of which was attached a barrel 
standing on the sixth floor fire escape landing. 
This barrel was provided with water from the 
city main. 

A quick-closing gate valve was installed on 
the 1%-inch pipe about 10 feet below the bot- 
tom of the barrel, and about 2 feet below the 
valve a 1%-inch Y branch and 45-degree el- 
bow, to which the "Geco" trap was attached. 

For purposes of testing, the barrel was filled 
and water discharged therefrom into the 1%- 
inch stack by opening the 1%-inch quick-clos- 
ing gate valve for three successive periods, 
said by the manufacturers' representative, 
who operated the valve, to be 3 seconds' dura- 
tion with 5-second intervals. No attempt was 
made by the operator to time himself by even 
an ordinary watch, much less a stop watch. I 
am convinced that the periods of flushing did 
not exceed 3 seconds each. 

The rate of flow through the 1^/^-inch pipe 
was not established, nor did the operator en- 
deavor to determine it; but it is certain that 
the pipe remained completely filled with water 
during the tests above the trap Y branch, and 
that therefore no vacuum existed within the 
vertical pipe itself. The partial vacuum in 
the branch trap connection was merely in- 
duced by the column of water passing down 
the main line. No attempt was made by the 
operator to determine the degree of vacuum. 

The test should have been made under con- 
ditions of flow resembling those occurring in 
actual plumbing installations, namely with a 
partially filled main. A vacuum would then 
have been created within the main, and the 
siphonic influence on the trap would have 
been considerably greater in consequence. 

The use of a 1^-inch vertical riser used as 
a waste pipe is against the rules of the plumb- 
ing code which prescribes not less than a 2- 
inch pipe, which must be open at its top, and 
not closed as was naturally the case. 

The free discharge of the water from the 
open end at the foot of the 1%-inch stack 



26 



PLUMBING FIXTURE TRAPS 



does not in any way resemble actual condi- 
tions. The back pressure, which would have 
developed in the stack, had it been connected 
in the usual manner by a horizontal line to 
the house drain, was entirely absent and there- 
by created conditions of air pressure within 
the stack which differed essentially from those 
of actual plumbing installations. 

The absence of back pressure naturally 
failed to show the "blowing" of the trap which 
occurs in unvented plumbing stacks, con- 
nected by horizontal lines to ^he house 
drains. 

To the trained engineer the testing equip- 
ment and method of operation used by the 
manufacturers and apparently accepted by the 
New York City officials, seems naturally, in 
view of all these defects, most unscientific, in- 
conclusive and bordering on the ridiculous. 

It is inconceivable that the greatest city in 
the world should have attempted to determine 
the reliability of an apparatus which is in- 
tended to protect mankind against foul air 
produced from the decomposition of its own 
waste products, by ' means of a testing ap- 
paratus erected on a fire escape, entirely dis- 
connected from the plumbing system, com- 
pletely different from actual plumbing prac- 
tice, not even complying with the plumbing 
code, and operated in a manner similar to that 
used by children in playing with toys. 

2. IN THE HALLENBECK BUILDING 

It is my understanding, although not based 
on personal knowledge, that the Master Plum- 
bers' Association of Greater New York, be- 
cause of the attitude of the Board of Stand- 
ards and Appeals, and because the association 
considered the introduction of the amended 
plumbing code a serious public danger, re- 
quested His Honor Mayor Hylan of New York 
City, to have reliable tests made of the Geco 
trap when attached to a properly designed 
plumbing system in an approved manner. 

The mayor is reported to have requested 
that the representative of the Master Plumb- 
ers' Association, Hon. Wm. J. Flynn, confer 
with the chairman of the Board of Standards 
and Appeals, Hon. John P. Leo, and that they 
two agree on such proper manner of testing 
the trap in an existing building. 

I am informed that thereupon Mr. Leo, with- 
out giving due notice in sufficient time to the 
Master Plumbers' Association or its repre- 
sentative, proceeded to test the Geco trap in 



the existing Hallenbeck building, located at 
the southeast corner of Pearl and Park streets, 
New York City, on May 1, 1919, and that he 
thereupon reported to the mayor that the tests 
had been made as suggested by him and had 
proven the trap satisfactory in every respect. 
It is my understanding that Mayor Hylan then 
took no further active interest in the matter. 




(1) The 5 X 2-Inch Plugged T-Y Fitting for 
Geco Trap Connection in the Hallen- 
beck Building 

While I did not witness test made by Board 
of Standards and Appeals in absence of an 
invitation or even notice, this test is described 
to some extent in the June 4, 1919, issue of 
the American Architect, reported to have been 
written by Edward F. Hammel, engineering 
editor, who was formerly the engineer of the 
board. Mr. Hammel I am told, acted as con- 
sulting engineer for the board, in the prepara- 
tion of the tests described by him. 

On May 2, 1919, the day after the test, I 
visited the Hallenbeck Building, saw what 
remained of the testing connections and appli- 
ances, and inspected the plumbing system to 
which the traps under test had been connected. 
I thereupon had the plumbing system meas- 
ured and six complete plans made of same, 
reproductions of which are shown in the ac- 
companying line engravings. 

That the method of testing the Geco trap in 



PLUMBING FIXTURE TRAPS 



27 







"^fSer^diC 



Plumbing in Basement, 1st and 2nd Floors of Building Where Geco Trap Was Tested 



28 



PLUMBING FIXTURE TRAPS 



■S'.Sey/S/a. 



^'^/oarPfx 



JVe/r^ from Lairs.ant/ WCon S/\/ f/o. 




PlumbiuR Layout of 3rd and 4th Floors of Hallenbeck Building, New York City 



PLUMBING FIXTURE TRAPS 



29 



S" C/ rrt7p^ 
ci S" F/oo ' 




3"C/ Frvp 
Ct/f^ed at CeVi/ia^-i^^ 



■Wf^/trtirra fiemo^fj 'from f*in /'/oer 



Plumbing Layout of 5th and 6th Floors of Hallenbeck Building, Neiv York City 



30 



PLUMBING FIXTURE TRAPS 






/io^gcd i/e/ii- Cor>^ ■ 



€l.aVaiories, 




Plumbing Layout of 7th and 8th Floors of Hallenbeck 
Building, New York City 



PLUMBING FIXTURE TRAPS 



31 







h-- 



Plumbing Layout of 9th and 10th Floors of Hallen- 
beck Building, New York City 



32 



1 



PLUMBING FIXTURE TRAPS 






^yi>/rt S/iKjf- 



-/*/7/ Moi/^e^*/* 



l/ot/'er Storoye 







tS^-temefT'/' ^/oo/-^ 









Plan Showing Riser and Drainage Lines of Hallenbeck Building, Where Geco Trap 
ITas Tested by New York City Officials 



PLUMBING FIXTURE TRAPS 



33 



the Hallenbeck Building was fully as unscien- 
tific and inconclusive as the previous one on 
the fire escape at 30 City Hall Place, will be 
readily understood. 

The Geco trap to be tested for resistance to 
siphonage was connected to the 5-inch stack 
near its foot on the first floor, while fixtures 
were discharged into this stack on nearly 
every floor above. 

Under these conditions there is no vacuum 
at the trap connection, consequently no trap 
siphonage. There exists on the other hand, 



ent; in fact, it is equally as absurd as testing 
a metal sample for tensile strength by com- 
pression tests. 

The accompanying photo No. I shows the 
5x2 plugged T-Y fitting for the "Geco" 
trap connection, and also the disconnected 4- 
inch vertical vent stack and 2-inch horizontal 
branch vent connection. The 4-inch stack to 
the left of the 5-inch soil stack is in actual 
practice intended to serve as a floor drain 
waste. 

The accompanying photos, Nos. 2 and 3, 




(2) Method Used on 5th Floor for Connecting Discharge Pipes to Lead Bends 



positive pressure, consequently back pressure 
and resultant blowing of the trap. 

Mr. Hammel says: "The anti-siphon trap 
lost no seal from siphonage." 

This statement is perfectly true; but Mr. 
Hammel, I am sure, could not expect that it 
would. Had he placed the trap connection on 
an upper floor the siphonage would have been 
most pronounced. 

Why he placed the trap in a position prac- 
tically free from siphonic action to prove its 
capacity of resisting siphonage is not appar- 



show the method used on the fifth and' seventh 
floors (from which the plumbing fixtures had 
been removed) to connect the discharge pipes 
of the 25-gallon tank to the lead bends by 
putty joints. 

That the board should have permitted putty 
joints in a testing apparatus said to repre- 
sent actual conditions of plumbing, and on the 
results of which they reported to Mayor Hylan, 
discounts the value of its findings. This is 
especially true, since these putty joints occur- 
red in the outlet waste pipe from the Geco 



34 



PLUMBING FIXTURE TRAPS 



traps placed under the tanks on the fourth, 
fifth and seventh floors. 

Such putty joints aie not air tight, even 
with the best of intentions, and the admission 




(3) Method Used on 7th Floor of the Hallen- 
beck Building, New York City, for Con- 
necting Discharge Pipes to Lead Bends 

of only relatively small amounts of air into a 
waste pipe, whether 'through leaky joints or 
through vent pipes, prevents the complete 
siphonage of any traps. Hence the fact that 
these Geco traps, which were inserted in the 
tank waste lines on the fourth, fifth and 
seventh floors did not siphon, is no proof of 
their siphonage resisting qualities. 

Mr. Hammel, to be sure, does not, as a mat- 
ter of fact, report in his American Architect 
article, that these traps did or did not lose 
their water seal; but if they retained a part 
of it, it was due to refill from the tanks to 
which they were connected, to leaky putty 
joints, and in addition thereto to a further 
and still more serious condition which must 
have been overlooked by Mr. Hammel and the 
board members. 

This condition was found in the fact that 
several basin traps connected to the 5-inch 
soil pipe were unvented % S traps, which at 
once, upon the creation of a slight vacuum in 
the stack, would have their seals broken and 



thereafter act as vent pipes, admitting sufifi- 
cient air to destroy any vacuum immediately. 
That this condition existed is shown in the 
accompanying photos, Nos. 4, 5, 6 and 7. No. 
4 shows the 4-inch floor drain, 5-inch soil and 
4-inch vent stacks on the eighth floor, and to 
their left a battery of five basins with an un- 
vented % S trap. No. 5 shows a close view of 
this same trap with its vent connection 
plugged. 

No. 6 shows a battery of three basins, also 
with an unvented Vz S trap on the ninth floor. 
No. 7 shows in the upper left-hand corner the 
continuation at the ninth floor ceiling of the 
unvented waste connection of the 5-basin bat- 
tery on the eighth floor, this 2-inch waste dis- 
charging into a 4-inch T-Y. 

Photo No. 7 also shows near the upper right 
corner the continuation of the unvented 2-inch 
waste line from another battery of basins on 
the eighth floor. The bracket seen in the cen- 
ter of the photograph was used to support one 
of the 25-gallon tanks. 

Although these photographs were made on 
the day following the tests of the Board of 
Standards and Appeals, it will be noted that 
the tanks and other appurtenances of the test- 
ing apparatus had already been removed. 

The tests made by the Board of Standards 
and Appeals at the Hallenbeck Building 
therefore lacked that careful workmanship and 
design of testing apparatus which is essential 
for all important tests, in the following par- 
ticulars : 

1. No vacuum, but rather a positive pres- 
sure, existed in the 5-inch stack on the first 
floor, where the Geco trap was connected for 
siphonage test. 

2. The Geco traps tested for siphonage on 
the fourth, fifth and seventh floors were in- 
serted in waste pipe lines having putty joints 
on the sewer side of the traps. The admission 
of air through such joints and the resulting 
breakage or prevention of a vacuum are quite 
probable. 

3. The vacuum in the entire system was 
largely diminished or perhaps entirely pre- 
vented by the admission of air through the 
unvented Vz S basin traps on the eighth and 
ninth floors. 

4. Any slight loss of seal which might have 
been caused in the Geco traps on the fourth, 
fifth and seventh floors, was restored by refill 



PLUMBING FIXTURE TRAPS 



35 




(4) Battery of Basins with % S Trap on 8th Floor, with Soil and Vent Stacks 



at the cessation of the discharge from the 
tanks. 

Mr. Hammel reports that the water seal of 
a .vented V2 S trap, connected on the first floor 
in place of the unvented Geco trap and vented 
into the 4-inch vent stack fluctuated consider- 
ably at each discharge, due to siphonic action, 
but that the seal of the trap remained un- 
broken. 

No record is given by him nor was there 
apparent any trace of the existence of any vent 
connection to the 4-inch stack on the day fol- 
lowing the tests, as is shown in photograph 
No. 1, although the Geco trap tests were made 
in the morning, the vented Vz S trap tests in 
the afternoon, and my inspection on the fol- 
lowing morning. 

TESTS AT 366 WEST BROADWAY, N. Y. 
CITY, UNDER MY DIRECTION. 

(A). GENERAL DESCRIPTION 
The building is of the 5-story loft type, 
and has a cellar and a flat roof. The story 
heights, beginning at the 1st floor, are 16 feet 
6 inches; 13 feet 2 inches; 12 feet 2 inches; 
11 feet 8 inches, and 11 feet 10 inches. Dur- 
ing the tests it was generally unoccupied, ex- 
cept on the 3rd floor and for a short period 



also on the 1st floor. Its floor area is irregular, 
but approximately 18 feet by 30 feet. 

It has a 4-inch extra heavy cast iron soil 
and 3-inch vent stack from cellar to roof and 
connected thereto on each floor, one water 




(5) A Close View of ^ S Trap, with Vent 

Connection Closed Under Basin Shown 

in No. 4 



36 



PLUMBING FIXTURE TRAPS 




(6) A Battery of 3 Basins on 9th Floor with Unvented ^ 5 Trap 



closet and one washbasin. In addition there 
is a 4-inch extra heavy cast iron inside leader 
and a 3-inch outside leader. The soil and 
leader stacks discharge in the cellar into the 
5-inch extra heavy cast iron house drain which 
has a 5-inch house trap and 4-inch fresh air 
inlet. 

The water closet and basin traps are indi- 
vidually back vented into the 3-inch vent 
stack, which formerly was re-connected into 
the 4-inch soil stack, near the ceiling of the 
5th floor, but which was, for the purposes of 
tests, run separately through the roof. 

B. TESTS OF VENTED Vo S AND UN- 
VENTED ANTI-SIPHON TRAPS WHEN 
CONNECTED TO 4-INCH SOIL AND 
3-INCH WASTE STACKS 
4-Inch Soil Stack 

The fixtures on the 5th floor were disconnected 
from the stacks, so that the traps under test 
could be attached to the latter. The 4-inch 
T-Y connection for the water closet was 
plugged; the 4 X 2 Y waste branch for the 
basin was retained, as was also the 3 x 2 tee 
vent branch in the vent stack. Photographs 
Nos. 8 and 9 show the arrangement to be as 
follows : 

A 1^-inch screw pipe connection on the 
continuous waste and vent principle was made 
between the 4 x 2 Y and the 3x2 tee. In this 
connection were inserted a 1%-inch plugged 



drainage Y and 1%-inch drainage T-Y, a 2- 
inch gate valve and a 1%-inch companion 
flange. The purpose of the Y and flange was 
to permit inspection of the waste and vent by 
any one interested; that of the T-Y was to at- 
tach the trap under test; that of the gate, to 
provide means for control of the trap vent. 
Anti-siphon traps were tested with the gate 
closed as in photograph No. 9; ^^ S traps 
were tested with it open, as in photograph 
No. 8. 

The vertical distance between the 4 x 2 Y 
and the 3x2 tee was 36 inches; between the 
4 x 2 Y and the l^^-inch T-Y, 12 inches. 

At a point 8 feet above the 4x2 Y, a 4x3 
tee branch, which had formerly received the 
3-inch vent stack, was removed and a 4 x 4 Y 
substituted. To this Y a 2%-inch pipe with 
quick-opening gate valve was connected, run 
up through the roof and connected to a 500- 
gallon roof tank. The gate valve was cali- 
brated so that for certain positions of the valve 
discharge rates of 50, 100, 150 and 300 gal- 
lons per minute were obtained. 

The traps were attached to the 1%-inch T-Y 
noted above and water discharged from the 
roof tank at these predetermined rates; the 
tests were made also with various reductions 
in the opening of the top of the soil stack to 
allow for hoar frost closure and to produce 
increased air friction as would obtain, if the 
soil stack were increased in height. 



PLUMBING FIXTURE TRAPS 



37 



In general, anti-siphon traps were tested for 
their siphonage resisting qualities under the 
various rates of discharge mentioned, namely, 
50, 100, 150 and 300 gallons per minute, and 
also under the various soil stack opening re- 
ductions from 4-inch diameter to 1-5/16-inch 
(1^/4-inch nipple), 1-inch (1-inch nipple); 
9/16-inch (%-inch nipple). 

In addition thereto, some of the traps were 
placed under test at distances varying from 
12 inches to 7 feet from the 1%-inch T-Y, and 
elbows were inserted besides to determine 
what, if any, influence the distance of an anti- 
siphon trap from the stack and any bends in 
the waste line would have on its loss of seal. 
These tests showed conclusively that anti- 
siphon traps placed at 7 feet distance from 
the stack with three drainage 45-degree el- 
bows, one drainage T-Y and one drainage 90- 
degree elbow, lost as much seal as when 
placed within 12 inches from the stack. The 
air is exhausted so rapidly from the long 
■waste lines that the vacuum is exerted almost 
instantly on the trap seal. 

The tests were made by discharging water 
from the roof tank for three 5-second periods 



into the 4-inch soil stack with 5-second in- 
tervals between successive flushes. The seal 
retained was read after each discharge. The 
traps were not refilled until after the comple- 
tion of the three flushes. Considerable care 
war exercised in the determination of the 
"Dead Line" as well as of the water level of 
the trap seal after each discharge. 

These measurements were made by the in- 
sertion of a %-inch glass tube into the trap 
from above. The glass tube passed through a 
rubber stopper fitting very snugly, the bottom 
of the stopper resting on the top of the trap 
inlet. The tube would then fill with water to 
the trap level; it was closed by the finger at 
the top, removed from the trap and the dis- 
tance measured from the underside of the 
stopper to the water level in the tube to the 
liearest 1/16-inch. 

The "Dead Line" of a trap, for which term 
1 am indebted to Albert L. Webster, is that 
water level which, if slightly raised will seal, 
and if slightly lowered will unseal a trap. In 
the determination of the "Dead Line" the trap 
was filled with water approximately to the 
"Dead Line" level. The mouth was then ap- 




(7) Unvented Waste Connection on 9th Floor Ceiling of a Battery of Basins 



38 



PLUMBING FIXTURE TRAPS 




(8) Showing Installation of V2 S Traps for 

Test at 366 West Broadway, New 

York City 

plied to the trap inlet and a slight breathing 
pressure exerted. If bubbles of air were 
forced through the water, the level was too 
high and a slight amount of water was taken 
out of the trap until the breath could be felt 
to pass into the trap without causing the for- 
mation of bubbling or of vibration of the 
water level. Since each trap was fitted with a 
glass window it was comparatively easy to 
make observations on this point, and it is my 
opinion that the "Dead Line" of each trap 
was fairly established to within 1/16-inch. 
Greater accuracy than this was attempted and 
1 believe secured, but was hardly necessary, 
since a 1/16-inch depth of trap seal would be 
considered by anyone competent to judge as 
insufficient for practical purposes. 

When the "Dead Line" had been established, 
the glass tube was inserted into the trap, as 
stated above, then removed while its upper 
end was being held closed, and the distance 
measured between the under side of the stop- 
per and the water level in the tube. This 
measurement was recorded as establishing the 



distance of the "Dead Line" of each trap be- 
low the top of its. inlet end. 

The trap was then filled with water to its 
overflow level and its distance below the top 
of trap inlet pipe measured by means of the 
glass tube in the same manner. This meas- 
urement was also recorded. The difference 
between the distance of the "Dead Line" and 
of the overflow line below the top of the trap 
inlet pipe gave the depth of the trap seal 
which was recorded in each instance. 

Measurements of the water level were de- 
termined in each trap after each test in a 
similar manner, and when deducted from the 
"Dead Line" distance gave the remaining trap 
seal, which was also recorded in each instance. 

The tests were made by discharging water 
from the roof tank for three 5-second periods 
into the 4-inch soil stack with , 5-second in- 
tervals between successive flushes. The seal 
retained was read after each discharge. The 
traps were not refilled until after the comp- 
pletion of the three flushes. 

A list of the traps submitted to tests, and 




(9) Showing How Anti-Siphon Traps Were 

Connected Up for Testing Purposes in the 

Building at 366 W, B'way, N. Y. City 



PLUMBING FIXTURE TRAPS 



39 



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flj -i-l 

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Drum 

Geco 

Sanito 

Hydric 

Wolverine 

Monarch 

Cudell 

Femco 

U. S. Hous 


ing Corp. 
Sanitas 
l^S Vented 


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detail information on same as collected by me, 
is given in Table F. 

This table shows that the anti-siphon traps 
tested hold from 4 to about 6 times as much 
water as the Vz S trap, and that their mean 
theoretical cross section area, calculated by 
dividing their total water capacity by their 
depth "of seal, is about 2 to 5 times as great, 
and therefore the average velocity of water 
passing through them is only about % to 1/5 
that passing through the Vz S trap. This is 
important, of course, since the reduction in 
velocity and the increase in storage capacity 
materially increase the rapidity of fouling. 

Appearing herewith is a series of 11 charts, 
one for each trap, tested at 366 W. Broadway, 
New York City, which show in graphic form 
the inches of seal, retained by each of these 
traps after each of the three 5-second flushes 
at the 50, 100, 150, and 300 gallons per min- 
ute or their equivalent of 5/6, 1-2/3, 2^ and 
5 gallons per second rates and with the various 
diameters of opening of the soil stack above 
the roof, as previously stated, namely 4-inch, 
1-5/16-inch, 1-inch and 9/16-inch. 

Referring for instance to the Geco trap 
sheet (Chart No. 1 on next page) the upper 
left rectangle represents the tests made with a 
4-inch or full opening at the top of the soil 
stack. The Geco trap has a normal depth of 
seal of 4^/4 inches. When tested under succes- 
sive 5-second flushes at the rate of 5 gallons 
per second, or 300 gallons per minute, the seal 
retained after the first 5-second flush was 
0.15-inch; after 2nd 5-second flush, 0-inch, 

On the same chart the upper right-hand 
rectangle represents similar tests, but with the 
4-inch soil stack opening reduced to 1-5/16- 
inch. Under this condition, the discharge of 
2% gallons per second, or 150 gallons per 
minute, lowered the trap seal after the first 
5-second flush to 0.5-inch, after the second 
one to 0.32-inch, after the third to 0.25-inch, 
after the fourth it remained at 0.25-inch, and 
after the fifth it dropped to 0,10-inch. 

Again, referring to the lower left rectangle 
on the same chart, showing the Geco trap test 
with the soil stack aperture reduced to 1 inch 
above the roof, the chart shows that the 2% 
gallons per second rate flushes reduced the 
trap seal to 0,38-inch after the first, 0.32-inch 
after second, 0.17-inch after third, 0.12-inch 
after fourth and 0.10-inch after fifth flush. 

Reference to the lower right rectangle, giv- 



40 



PLUMBING FIXTURE TRAPS 





-r 




< 








Jo 
^~1 




> 


^ 


A 


<5 




.1 



PLUMBING FIXTURE TRAPS 



41 



mg the test results for the Geco trap with a 
9/16-inch soil stack opening, shows that the 
first flush at the 1-2/3 gallons per second rate 
lowered the seal to 0.35-inch and the second 
flush to 0-inch; also that the first flush at the 
2^/^ gallons per second rate broke the seal. 

It would be too lengthy to attempt herein 
a complete dissection of all of the tests of 
all the traps, but in addition to the Geco, it 
would seem pertinent to give some detailed 
consideration to the U. S. Housing Corpora- 



tion (Chart 9), and to the V2 S vented (Chart 
11) traps. 

The U. S. Housing Corporation trap, manu- 
factured by the Sanitary Company of America, 
Linfield, Pa., and sold by it under the name of 
the "Saaco" anti-siphon trap, showed the fol- 
lowing test results, for which see Chart 9: 

4-inch soil stack opening, 2% gallons per 
second flushes, after first flush 0.25-inch seal 
retained; after second flush 0.08-inch seal re- 
tained; after third flush 0.0-inch seal retained. 
1-5/16-inch soil stack opening, 2^/^ gallons per 



TABLE G 

Comparative Tables Showing Siphonage Resisting Capacities of the Unvented "Geco" and "U. S. 
Housing Corporation" or '^Saaco" Traps and the Unvented V2 S Trap 



A. 4-Inch Soil and 
Rate of 
Name of Flush in 

IV2 in. Traps gal. per min. 

Geco 50 

U. S. Housing Corp 50 

Vented 1/2 S 50 

Geco ICO 

TJ. S. Hou3ing Corp 100 

\ented 1/28 100 

Geco 150 

U S. Housing Corp 150 

Vented %S ^....150 

Geco 300 

U. S. Housing Corp 300 

Vented % S 300 



Vent Stack Openings 

Seal Retained by Traps After 

1st 5 Sec. 2nd 5 Sec. 3rd 5 Sec. 

Flush Flush Flush 

4.25 in. 4.25 in. 4.25 in. 

3.38 in. 3.38 in. 3.38 in. 

2.25 in. 2.25 in. 2.25 in. 



3.63 in. 
2.70 in. 
2.25 in. 


3.50 in. 
2.58 in. 
2.18 in. 


3.32 in, 
2.50 in. 
2.05 in. 


2.75 in. 
0.25 in. 
2.00 in. 


2.50 in. 
0.08 in. 
1.82 in. 


2.50 in. 
0.00 in. 
1.75 in. 


0.15 in. 


1.68 in. 





1.62 in. 





1.62 in, 



B. 1 5/16-Inch Soil and 
Rate of 
Name of Flush in 

1% in. Traps gal. per min. 

Geco 50 

U. S. Housing Corp 50 

Vented 1/2 S 50 

Geco 100 

U. S. Housing Corp 100 

Vented 1/2 S 100 

Geco 150 

U. S. Housing Corp 150 

Vented %S 150 

Geco 300 

U. S. Housing Corp 300 

Vented 1/2 S 300 



Vent Stack Openings 

Seal Retained by Traps 



1st 5 Sec. 
Flush 
3.75 in. 
3.12 in. 
2.25 in. 

3.12 in. 
2.50 in. 
2.12 in. 

0.50 in. 
0.08 in. 
1.88 in. 
0.08 in. 
0.00 in. 
1.68 in. 



2nd 5 Sec. 
Flush 
3.68 in. 
3.0 in. 
2.18 in. 

2.90 in. 
2.38 in. 
2.0 in. 
0.32 in. 


1.75 in. 




1.62 in. 



After 

3rd 5 Sec. 
Flush 
3.68 in. 
3.0 in. 
2.12 in. 

2.82 in. 
2.25 in. 
1.88 in. 

0.25 in. 


1.75 in. 



1.62 in. 



42 



PLUMBING FIXTURE TRAPS 



C. 1-Inch Soil and Vent Stack Openings 

Rate of Seal Retained by Traps After 

Name of Flush in 1st 5 Sec. 2nd 5 Sec 3rd 5 Sec. 

1% in. Traps gal. per min. Flush Flush Flush 

Geco 50 3.82 in. 3.75 in. 3.75 in. 

U. S. Housing Corp. 50 3.12 in. 2.92 in. 2.92 in. 

Vented 1/2 S 50 2.25 in. 2.12 in. 2.00 in. 

Geco 100 2.75 in. 1.32 in. 1.05 in. 

U. S. Housing Corp 100 2.00 in. 1.18 in. 0.42 in. 

Vented 1/2 S 100 2.00 in. , 1.88 in. 1.82 in. 

Geco 150 0.38 in. 0.32 in. 0.18 in. 

U. S. Housing Corp ...150 

Vented Vo S 15.0 1.75 in. 1.68 in. 1.62 in. 

Geco 300 

U. S. Housing Corp 300 

Vented 1/2 S ......300 1.62 in. 1.62 in. 1.50 in 



D. 9/16-Inch Soil and Vent Stack Openings 

Rate of Seal Retained by Traps After 

Name of Flush in 1st 5 Sec. 2nd 5 Sec. 3rd 5 Sec. 

1^/^ in. Traps gal. per min. Flush Flush Flush 

Geco 50 2.95 in. 2.80 in. 2.75 in. 

U. S. Housing Corp 50 2.38 in. 2.30 in. 2.25 in. 

\ented ¥2 S 50 2.12 in. 2.0 in. .1.88 in. 

Geco ....: 100 0.35 in. 

U. S. Housing Corp.. 100 

Vented 1/2 S 100 1.88 in. 1.75 in. 1.75 in. 

Geco 150 

U. S. Housing Corp 150 * 

Vented 1/2 S 150 1.38 in. 1.32 in. 1.18 in. 

Geco 300 

U. S. Housing Corp 300 

Vented 1/2 S 300 0.75 in. " 



second flushes, after first flush 0.08-inch seal 
retained; after second flush 0.0-inch seal re- 
tained. 1-inch soil stack opening, 2^/^ gallons 
per second flushes, after first flush 0.0-inch 
seal retained. 9/16-inch soil stack opening, 
1-2/3 gallons per second flushes, after first 
f!ush 0.0-inch seal retained. 

The V2 S trap, vented, showed these test re- 
sults, for which see Chart 11 : 4-inch soil 
stack opening, 5 gallons per second flushes, 
after first flush 1.68-inch seal retained; after 
second flush 1.62-inch seal retained; after 
third flush 1.62-inch seal retained. 1-5/16- 
inch soil stack opening, 5 gallons per sec- 
ond flushes, after first flush 1.68-inch seal 
retained; after second flush 1.62-inch seal re- 



tained; after third flush 1.62-inch seal retained. 
1-inch soil stack opening, 5 gallons per second 
flushes, after first flush 1.62-inch seal retained; 
after second flush 1.62-inch seal retained; 
r.fter third flush 1.50-inch seal retained. 9/16- 
inch soil stack opening, 5 gallons per second 
flushes, after first flush 0.75-inch seal retained; 
efter second flush 0-inch seal retained. 

For purposes of easier comparison between 
the siphonage resisting capacities of the un- 
vented "Geco" and "U. S. Housing Corpora- 
tion" or "Saaco" traps and the vented V2 S 
trap. Table G has been prepared (original 
trap seals, Geco 4.25-inch; U. S. Housing 
Corp. 3.63-inch; V2 S 214 inch). 

While similar comparative tables can readily 



PLUMBING FIXTURE TRAPS 



43 



" 


S".', ^' ^- , 


































- 




? : 


, 






















, " ~~--_^ t'^'"'- 






^-~ — 


^ 










-_,5i22i^ 


r. 


i ^'':v~££c--^^ 


^ -5 /O JS u ,-f ,c- ~ 7 





(2) Consecutive Tests of 5 Seconds' Duration of lV2-Inch Sanito Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



be prepared of the other anti-siphon traps 
tested, this would seem unnecessary in view of 
the charted curves of the test records, which 
are easy of interpretation and comparison 
for any particular trap under any particu- 
lar test condition. In general it will be found 
that the other anti-siphon traps exhibited 
similar absence of siphonage resisting powers 
under conditions which they should be capable 
of withstanding as successfully as did the 
vented V2 S trap. 

A brief study of preceding tabulations, 
which are typical of practically the entire 
field of anti-siphon traps (except those found 
so weak in preliminary tests as to be ex- 
cluded from consideration) shows that out of 
16 series of test runs each run having 3 
flushes) , under varying conditions of flush- 
ing rates and stack openings, the Geco trap 



seal has a record of complete breakage 
6 times ^38 per cent and a record of 
^/^-inch or less trap seal retained 8 times =50 
per cent.; the U. S. Housing Corporation of 
complete breakage 9 timesi=56 per cent and 
of %-inch or less trap seal retained 10 times = 
62 per cent and the % S vented trap of com- 
plete breakage .and of ^/^-inch or less trap 
seal retained only once=:6 per cent and that 
under the most severe conditions purposely 
imposed to determine the limit of resistance 
of the vented V2 S trap. 

No competent, unbiased sanitarian can con- 
sistently claim, I believe, that a %-inch trap 
seal is sufficient. The wave action which fre- 
quently occurs persistently in trap water 
seals, due to wind, tides and other outside in- 
fluences, would quickly and completely de- 
stioy such a small seal or send pufFs of sewer 



44 



PLUMBING FIXTURE TRAPS 







i 



^ 






% I 

c~ i 






I 



^- 



9) 



-£_ 






K) •«\l -v < 



K5 ty -- <s> 



<o j I 



V 1 



V) 






'^H^ 



i5 ,^ 






C-, t 



^1 I 

I 



/ 



I / 
f / 



/ / 



! ^/ 



f^ 






4:: 



--I- 



c>^d<::v,y 



.'a S'S'i/'S'L-/ 



60 



o 



c/3 

§ 
fee 









c 



o 






o 



PLUMBING FIXTURE TRAPS 



45 






'I'.Openjrfp or Tap o/ ^o// ^'-foc*<. 



\ 


Kr^~——--^^ i9P-s- 


^r====^ 




■ . 1 


\ ^ 




/^p.ff.iS- 














~~-^ 1 




\ — 



/^-J Gpen/n(j at Top of t5c// Sioc/<. 




CAs^horgs Per/ixf/.n 'Sisconcfs. 



/' Op^ry'/jp a/ Top o/ -So// SroCf< 



U'Sc/jarp^ PsHoc/ />7 6'SQO.nd^. 



% Optsn/fiff cr/ Top o/ •Sot/ Stcrc/f- 



#?■.-=■• ^~ 




D'-scfyaf-^e 



vac/ /'n 'SscOjnc^s. 



D/^c/rays , 






(4) Consecutive Tests of 5 Seconds' Duration of IVa-Inch Hydric Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



air through it; and no plumbing system hav- 
ing such small trap seals would withstand 
even a ridiculously lax smoke test. 

It will be noted further that the least severe 
conditions under which the Geco trap seal was 
destroyed were those having a 1-5/16-inch soil 
pipe aperture and a 150 gallon per minute 
flushing rate; the U. S. Housing Corporation 
trap yielded under the still less severe con- 
dition of a 4-inch stack opening and a 150 gal- 
lon per minute flushing rate; the vented Vo S 
trap seal was broken only with a 9/16-inch 
slack opening and a 300 gallon per minute 
flushing rate. 

A f3w words should be said at this point 
about the degree of severity of the tests to 
which the traps were subjected. To me they 
ao not appear as excessively severe, but in- 
tensely practical, for the following reasons: 



1. The flushing rate of 150 gallons per 
minute (equivalent to 2^/^ gallons per second) 
represents the simultaneous discharge rate of 
only 2 siphon jet or siphon action water 
closets, supplied with the usual type of flush 
^alves which operate at a rate of about 1 gal- 
Ion per second. The actual rate of discharge 
from a water closet into the soil pipe exceeds 
the inflow rate of 1 gallon per second into 
the water closet bowl, since the latter dis- 
charges during its action not only the inflow, 
but in addition thereto its own contents. The 
outflow is thereby increased over the inflow 
rate by about ^ gallon per second, and the 
maximum simultaneous discharge rate of two 
water closets becomes actually 2^/^ gallons per 
second. 

2. The decrease in area by hoar frost of a 
4-inch soil pipe to an opening 1 5/16-inch 



46 



PLUMBING FIXTURE TRAPS 



diameter may reasonably be expected after 
extended cold weather periods. 

3. Since the traps tested were in new and 
thoroughly clean condition their siphonage 
resisting strength was at its maximum. It is 
decreased materially by fouling of the traps in 
use, and due allowances must therefore be 
made in any similar test of clean traps to pro- 
vide for this future weakness of traps after 
fouling. There are no records available to 
show the degree of loss in siphonage resist- 
ing power of traps by fouling, so that no defi- 
nite estimate can be made of the proper in- 
crease in testing requirements, 

4. No engineering structures are generally 
considered as being properly or competently 
designed unless they have a factor of safety 
which is usually not less than 1.5 nor more 
than 4. I need not go into the fields of struc- 
tural engineering to show this fact; in plumb- 
ing engineering high factors of safety^re con- 



stantly allowed by all of our able men and 
prescribed by all of our progressive cities. 

Plumbing pipes and fittings, their sizes, the 
methods of joining them, are all in excess of 
their actual needs; every able architect, engi- 
neer and health official will agree that the 
water and smoke tests of plumbing work are 
most essential to secure good work, and yet no 
soil, waste or vent pipe system is ever exposed 
to anywhere near the water or sewer air pres- 
sure in actual practice, to which it is exposed 
in this official preliminary water test. 

It is a matter of wisdom always and invari- 
ably to provide for a factor of safety, and it is 
fully as necessary to keep sewer air from en- 
tering the building through a siphoned trap 
as it is through leaky pipe joints, for both are 
unsanitary. 

5. It was established that under the testing 
conditions as described to have existed at 366 
W. Broadway, the breaking load of the .Wo- 



ti n ~ ' T 






-4 



, l'/i3<sricy/xi&. /^n'Of^ in •SisciO/^c/^'i- 



1 1 







^" Ope/^;rij ar fy of -So 'J A^.:"; 



\^. 



-ff-^ 



,=_f. 



( Sjsc^k!^^ fk\oe/ j"/} iS^e^a^ais 



(5) Consecutive Tests of 5 Seconds' Duration of iVo-Inch Wolverine Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



PLUMBING FIXTURE TRAPS 



47 



■^'A'n, Opin;np arTop of ■So// SfacM 



"a. ^'Openl/T9 at '7bj:!o^ 'So// 'Sfac/^- 



£9 i'i •/ ope'71'ys^ ' 




■: .- 




_^ 


-~ 'Jil-li 






<°^.-,^^ 





/y 9f>^- / <?/*'5'/;7f , : 





I'/SC/Xir^ Pf^rfCc/ •'7 JVco/70'j? 









(6) Consecutive Tests of. 5 Seconds' Duration of lV2-Inch Monarch Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



inch half S trap, vented by a 1%-inch con- 
tinuous vent, occurred with a 9/16-inch stack 
opening and a 300 gallons per minute flush- 
ing rate. No anti-siphon trap has developed 
this strength within even reasonable limits. 
The % S vented trap has been and is now ac- 
cepted country-wide as the standard require- 
ment; no article offered in substitution can 
lope to successfully compete with it, unless 
it proves itself equally as strong in the most 
vital essential, namely, power of resistance to 
siphonage. 

6. The depth of seal of the anti-siphon 
traps exceeds that of the V2 S trap tested 
under identical conditions with one exception, 
the Cudell trap. Generally, this excess is quite 
large, as for instance in the U. S. Housing 
Corporation trap by 61 per cent and in the 
Geco trap by about 90 per cent. 

It is well known that an increase in depth 
of seal of a trap will increase its resistance to 
siphonage. Hence, if the vented % S trap had 
liad the same depth of seal as the anti-siphon 
traps tested, the results would have been more 
comparative as to actual siphonage resisting 
power of the two types of traps. 

For this reason I have prepared a series of 
curves, presented on the following pages, as 
Charts 12 to 21, which show a comparison of 
the percentage losses of seal of each of the 
anti-siphon traps with the vented V2 S trap. 



Each chart refers to only one of the anti-siphon 
traps, and the percentage losses of this trap 
are shown in full lines, while those of the 
vented V2 S traps are indicated in dash lines. 

Referring to chart 12 which shows the com- 
parison of the percentage losses of seal of the 
Geco trap with the vented % S trap, it will 
be found that this chart is divided into 4 sets 
of curves, each set covering one of the four 
rates of flushes used in the tests. In each set 
are plotted the curves representing the per- 
centage losses of seal with the different sizes 
of stack openings, one curve being for each 
size opening, and each curve being designated 
with the size of opening for which it repre- 
sents the test results. 

Bearing in" mind that the full line repre- 
sents always the anti-siphon trap and the dash 
the % S trap seal losses, it is apparent at a 
glance that, wherever the dotted % S trap line 
for any particular size stack opening is on the 
left of the full anti-siphon trap line for the 
same size stack opening, the vented V2 S trap 
had a smaller percentage loss of seal than the 
anti-siphon trap, and vice versa. 

Further, on the left of each set of curves 
will be found the words, "Discharge Period 
in Seconds," which is divided into 5, 10 and 
15-second periods and represents the three 
successive flushes of 5 seconds each. As a 
concrete example, to determine the compara- 



48 



live percentage losses of seals of the vented 
V2 S and the Geco traps, when the discharge 
rate was 2^/^ gallons per second (150 gallons 
per minute) and the stack opening above the 
roof was 1-5/16 inches, at the completion of 
the first, second and third 5-second flushing 
periods. The procedure is as follows: 

In the upper right of chart 12, covering the 
Geco trap, note the given rate of discharge of 
2% g. p. s., for the series of curves marked 
1-5/16-inch opening. 

On the left of the set of curves note "Dis- 
charge Period in Seconds," for the 5, 10 and 
15-second periods. 

To determine the percentage seal loss of 
the V2 S trap after the first 5-sccond flush, 
read horizontally along the 5-second line to 
its intersection with the dash line marked 
1-5/16-inch opening, then downward, and 
read off the percentage loss of seal of the % S 
trap to be twenty-two per cent. 

Continue again along the 5-second horizon- 
tal line to the right to its intersection with 
the full curve marked 1-5/16-inch opening 
and read downward, giving the percentage 
loss of seal of the Geco trap as eighty-eight 
per cent. 

To determine the losses after the 2nd and 



PLUMBING FIXTURE TRAPS 

3rd flushes, read horizontally along the 10 and 
15-second lines respectively, until they inter- 
sect .the same curves. Note the following 
losses to have taken place in the various tests: 
After 2nd flush, V2 S trap, 27% ; Geco trap, 
921/2%. After 3rd flush, 1/2 S trap, 27^/2%; 
Geco trap, 94^%, 

The percentage losses of other traps may 
be determined in a similarly easy way from 
the charts Nos. 12 to 21. It would lead to 
unwarranted lengthy tables to attempt a tabu- 
lation of the percentage losses of all traps, 
but table H gives these losses for the Geco, 
U. S. Housing Corporation and i/^ S vented 
traps. 

From this table it is at once apparent, as 
it is from the curves, that the percentage 
losses of seal of the two anti-siphon traps were 
far in excess of those of the vented % S traps, 
so far indeed in many instances, that their in- 
herent weakness to siphonage, inch for inch of 
depth of seal when compared with the V2 S 
trap, becomes striking and beyond doubt con- 
vincing. 

No better proof can possibly be asked than 
this to show the comparative inherent weak- 
ness of the anti-siphon type and the inherent 
strength of the V2 S vented type of traps. 






'i' Opening txt ^op of So// <Stac/< 






.-^'9,fi'.jS.. 



IJ 



■rJ-^-t: feri.i:,/ 



<*, 










ZH-ze'sZ 




::/rarue f-^erfoij /<>? tiVceA'o^" 



■ h '><i c^ fu/-^ of o"t?//* *5'?^c^r 




(7) Consecutive Tests of 5 Seconds* Duration of lV2-Inch Cudell Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



PLUMBING FIXTURE TRAPS 



49 



It is interesting to note from the table that 
in general the tests showed greater percentage 
losses of seal of the U. S. Housing Corpora- 
tion trap than of the Geco trap. It would 
seem therefore that the design of the former 
produces less resistance to siphonage, inch for 
inch of depth of seal» than the latter ; but even 
the latter proved its practical worthlessness in 
comparison with the % S vented trap, when it 
lost 100 per cent of its deep seal of 4^ inches 
as shown in the table, as against the % S trap 
only 25 per cent, of its shallow seal oi 2}k 
inches; the U. S. Housing Corporation trap 
made, as stated above, a still worse demon- 
stration, as shown in the table, when it lost 
100 per cent, of its seal against twenty- 
two per cent, loss of the One-half S trap. 

Throughout the tests, the recorded trap seal 
percentage losses of the anti-siphon traps 
run as high as 15 times those of the vented 
trap seal losses. 

This same general condition obtained in the 
comparison of the percentage of trap seal 
losses of all of the anti-siphon traps, some 
showing at times slightly greater strength, at 
times even much greater weakness. 

I am satisfied that the tests showed the ab- 
solute incapability of the anti-siphon traps to 
adjust themselves to the strain of meeting the 
conditions of actual service; they lacked the 
resiliency required to fill the vacuum created 
in the pipe lines, without spilling their seals 
to the danger point. 

Neither can this be wondered at; water is 
unyielding and objects to being compressed 
and expanded, whereas air, supplied through 
the vent connection of the Vz S trap is elastic; 
the slightest force moves it, compresses it, ex- 
pands it; it rushes in when needed and re- 
cedes as rapidly when present in excess. 

I doubt, if ever any anti-siphon trap can be 
designed and built on otherwise scientific prin- 
ciples, which will have that capacity of quick 
adjustment to the unnatural conditions of at- 
mospheric positive or negative pressure, cre- 
ated within the drainage system of a building 
whenever plumbing fixtures are discharged. I 
say this advisedly, for I found in the 4-inch 
soil pipe stack at 366 West Broadway the 
simultaneous existence of a vacuum of 36 
inches, another vacuum of 9^ inches, and a 
positive pressure of 40 inches of water column 
during the same conditions of discharge and 
otherwise at diff'erent parts of the stack; and I 
found a variation of 13% inches of water col- 



umn during the same discharge at the same 
location, namely, on the second floor. 

In a five-story building such as was used for 
our tests at 366 West Broadway, the atmos- 
pheric pressure within the soil stack, due to 
plumbing fixture discharges, varied from about 
30 to 40 ounces positive to about an equal 
amount negative. This means that within the 
same stack of a five-story building there exist 
at the same time air pressures differing from 
each other as much as 5 pounds. 

It is a matter for conjecture how great this 
difference must be in a tall office building; 
and yet the "simplified plumbing" advocates 
would have us believe that there are traps in 
existence which, without special air relief or 
supply or vent j)ipes, will adapt their 4-inch 
to 6-inch water seals promptly, unfailingly and 
successfully to such tremendous air pressure 
variations which I doubt do not reach half an 
atmosphere at times, in our skyscrapers. Such 
statements seem to me, in the present state of 
the art at least, preposterous and wild. 

Three'Inch Waste Stack 

Some reasons existed why additional tests 
should be conducted besides tho^e described. 
The 4-inch stack had fixture and branch con- 
nections on each floor below the fifth, which 
were thought to possibly have influenced to 
some extent the degree of vacuum. 

Also, since the first floor was occupied and 
was furnished with a vented toilet and vented 
V2 S trap wash basin, there were no means of 
ascertaining the intensity of the back pressure 
which we knew must exist in tiie lower reaches 
of any soU pipe stack, the foot of which was 
not properly relieved by a vent line. 

Furthermore, it was desirable to ascertain 
if possible, how much of a variation of the rate 
or discharge through different size stacks 
would be required to produce complete de- 
struction of the seal of anti-siphon traps. 

For these reasons a 3-inch extra heavy cast 
iron waste stack was erected in the stairwell 
of the building at 366 West Broadway, New 
York City, up through the roof, and connected 
at its foot in the cellar by a 3-inch extra 
heavy cast iron line about 10 feet long, having 
^•-inch fall per foot and two 90-degree long 
sweep bends, into the 5 x 3-inch extra heavy 
Y branch of the 5-inch house drain. The de- 



50 



PLUMBING FIXTURE TRAPS 



A. Rate of Discharge =5 
Name of Trap 
After 1st Flush 4" 

Geco 95.5% 



Gals, Per Second 

Diameter of Stack Opening 



H. C. 



u. s. 

1/2 s 

After 2nd Flush 

Geco 

U. S. H. C 

1/2 S 

After 3rd Flush 

Geco 

U. S. H. C 

y2S 



B. Rate of Discharge 



After 1st Flush 

Geco 

U. S. H. C 



After 2nd Flush 

Geco 

U. S. H. C 

y2S 

After 3rd Flush 

Geco , 

U. S. H. C 

1/2 S 



100% 
25% 

100% 

100% 

25% 

100% 
100% 

25% 

=21/2 Gals. 
4" 

35% 
93% 
11% 

41% 
98% 
19% 

41% . 
100% 
22% 



1 5/16" 
97% 
100% 
69% 

100% 
100% 
88.5% 

100% 
100% 
91.5% 

Per Second 
1 5/16" 
88% 
95.5% 

22% 

92.5% 

100% 

27.5% 

93% 
100% 

27.5% 



C. Rate of Discharge=:l 2/3 Gals. Per Second 



After 1st Flush 

Geco 15.8% 26.5% 

U. S. H. C 25.5% 31% 

y2S 11% 

After 2nd Flush 

Geco 17.5% 31% 

U. S. H. C 29.5% 34.5% 

y2S 2.5% 11% 

After 3rd Flush 

Geco ; 20.5% 33.5% 

U. S. H. C 31% 38% 

y2S 8.5% 11% 

. f 1 . 171 I- D. Rate of Discharge=5/6 Gals. Per Second 
Alter 1st J^lush 

Geco 10.3% 11.8% 

U. S. H. C 6.8% 13.8% 

y2S 

After 2nd Flush 

Geco 11.6% 13.2% 

U. S. H. C 6.8% 17.2% 

yaS 1.8% 

After 3rd Flush 

Geco 11.6% 13.2% 

U. S. H. C 6.8% 17.2% 

y^s 5.5% 



1" 
91% 
100% 

27.5% 

92.5% 
100% 

27.5% 

94% 

100% 

33% 

35% 

44.5% 
11% 

55% 
67.5% 
16.5% 

75% 
78% 
19% 



1" 
100% 
100% 
Not plotted 

100% 
100% 
Not plotted 

100% 
100% 
Not plotted 

9/16" 
100% 
100% 
38.5% 

100% 
100% 

44.5% 

100% 
100% 
58.5% 



Not plotted 
13.8% 

5.5% 

Not plotted 
19% 
8.3% 

Not plotted 
19% 
8.3% 



92.5% 
100% 
16.5% 

100% 
100% 

22.5% 

100% 
100% 

22.5% 



31% 
34.5% 
13.8% 

33.8% 
36.3% 
13.8% 

35.3% 
38% 

13.8% 



Table H. — Tabulation of Percentage Losses Found in Tests of Geco, U. S. Housing Corpora- 
tion and One-Half S. Vented Traps 



PLUMBING FIXTURE TRAPS 



51 



'lo cd Top c-f •3oj/ otaci 



i. " 
-.. 1^=^ — — 


_____ ^^vP.S. 


V 


'-§' 9fi-S 






r>: 




i ;A "~^^~"~^~^--^5.^. . 




^ • 


'■' 


icj' in S.fCono'S 



■^~z Oper>h^o czf Tox> c^ 'Jr// -S.'^C'**'- " 








. •• - 











■:f <:-.. 



/' Openinp ci^ 7hp o^ oa// SfacK. 




^'•^i - 


\ - •■ 




1' 

^ : 


\ 
\ 


'\ 


H. 

,. 


'a 












^ 










\ 







-- - 


\ 




n 


QS /tv, .. 




rfet;vt>-//r,^» or Tap v' •-' 

















'v 


'-? -j.t--; 






\ 




&, sc^CLrt^ Th.-zOa' '^/ -Si? 


scocfs: 



<8) Consecutive Tests of 5 Seconds' Duration of lV2-Inch Femco Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



tails of the 3-inch stack and its connections 
are hereinafter shown in plan and section. 

The total length of the stack was 74 feet 3 
inches. At a point 13 feet 9 inches above its 
foot it had a 3 x 2-inch Y and 13 feet 4 inches 
below its top a 3-inch by 1%-inch TY, both 
for connections of traps under test. 

At a point 6 feet 7 inches below its top, a 
3-inch by 2-inch Y was inserted and another 
similar fitting directly above. The former was 
connected by a 2-inch valved galvanized iron 
pipe to the bottom of a 53-gallon barrel; the 
latter by a 2-inch galvanized iron pipe without 
valve, but with a 2-inch % S lead trap and 2- 
inch brass bath waste connection and strainer 
purchased in the open market and identical 
with those used in the New York City Hotel 
Pennslyvania guests' baths. 

A 2-inch screw pipe vent stack was installed 



adjacent to the 3-inch waste stack and also 
extended through the roof. Its foot was 
dripped into the waste stack by a 3 x 2 Y and 
45-degree elbow in the usual manner, and a 2- 
inch valve was here inserted so that the 2-inch 
^ent line could be completely closed. 

On the fifth floor a 2-inch continuous waste 
and vent connection was made between both 
stacks in the usual manner, a 2-inch gate valve 
being also inserted on this 2-inch cross con- 
nection adjacent to the 3x2 tapped TY for 
controlling purposes, as shown in the detail 
section. 

In all tests of anti-siphon traps the 2-inch 
gate valve at the foot of the 2-inch vent stack 
and that in the 2-inch continuous waste and 
vent connection on the fifth floor were closed, 
except in certain instances »of demonstrations 
to visitors, who desired to see for themselves 



52 



PLUMBING FIXTURE TRAPS 



that the proper venting of the foot of a waste 
stack by drip vent connection removes com- 
pletely that enormous positive pressure which 
was found to exist in the lower reaches of the 
3-inch waste stack during the discharge of the 
bathtub or barrel on the roof. In such cases 
the 2-inch gate on the 2-inch vent drip connec- 
tion was temporarily opened. 

The tests of the anti-siphon traps were lim- 
ited largely to the Geco and the vented V2 S 
traps, although the other anti-siphon traps 
were tested merely to determine if they would 
lose their seals under the same conditions as 
the Geco, and it is stated here without future 
reference thereto, that the seals of all of the 
anti-siphon traps tested were completely or 
practically destroyed under the same condi- 
tions as that of the Geco trap. No attempt 
was made to determine if a smaller flushing 
rate would break the seal of any of these 
other traps. 

The seal of the Geco trap, when attached 
to the 3-inch by 2-inch tapped TY located 3 
feet 5 inches above the fifth floor and 13 feet 



4 inches below the top of the 3-inch stack, 
was found to be completely broken when 53 
gallon contents of the barrel were discharged 
into the 3-inch stack through the full open 
2-inch gate valve in 34 seconds, corresponding 
to an average discharge of 94 gallons per 
minute. 

It was found on further investigation that 
the 2-inch waste pipe from the barrel could 
be materially throttled, until the barrel dis- 
charged its 53 gallons in 42 seconds, corre- 
sponding to an average discharge rate of 76 
gallons per minute. 

Still further, when the barrel was full and 
its waste pipe gate valve wide open, a dis- 
charge of only 12 inches of its total depth of 
31^ inches, that is 19.2 gallons, were re- 
quired to completely destroy the Geco trap 
seal. 

The start and stop method of testing with 
three 5-second flushes, and 5-second intervals 
between flushes, was also tried. Under this 
test the Geco trap failed completely by break- 
age of its seal, the average flushing rate being 



?•'' 



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(9) Consecutive Tests of 5 Seconds^ Duration of iVi-Inch U. S. Housing Corp. Trap with 
Various Rates of Discharge and Sizes of Opening at Top of Soil Stack 



PLUMBING FIXTURE TRAPS 



53 



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(10) Consecutive Tests of 5 Seconds* Duration of 2-Inch Drum Trap with Various Rates 
of Discharge and Sizes of Opening at Top of Soil Stack 



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<11) Consecutive Tests of 5 Seconds' Duration of IVo-Inch Vented V2 S Trap with Various 
Rates of Discharge and Sizes of Opening at Top of Soil Stack 



54 



PLUMBING FIXTURE TRAPS 



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65 




Section Through Stair Wdl of Building at 366 W. Broadway, New York City, Showing 
'. 3-Inch Waste Stack and 2-Inch Vent Line z==^=====. 



66 



PLUMBING FIXTURE TRAPS 



111 gallons per minute. The same result was 
obtained when the 2-inch Geco trap waste 
pipe was extended 7 feet from the stack with 
two 45-degree and two 90-degree elbows be- 
tween traps and 3-inch stack. 

T! e bnthtub was then filled with water, the 
2-incx. gate en the barrel waste closed, and 
the bathtub discharged. A complete siphon- 
age of the trap seal took place as before. 

By repeated experiments it was found that 
the discharge of 35 gallons of water from the 
bathtub was sufficient to break the Geco seal. 
This discharge was at the average rate of 75 
gallons per minute; also that it was broken 
by 5-second flushes from the bathtub, with 5- 
second intervals, these discharges being at 
the average rate of 110 gallons per minute. 

I am satisfied that any trap connected to a 
3-inch waste stack in a five-story building, 
with the top of its waste line wide open, 
which, when brand new and clean, had its 
trap seal not merely decreased but entirely 
wiped out by the discharge of 35 gallons of 
water from a bathtub on a floor above con- 
nected to the 3-inch stack by means of a 2- 
inch waste pipe with a 2-inch standard % S 
trap and a standard 2-inch waste connection 
such as is used in connection with high class 
bathtub work, is unsafe and unfit for use. 

One of the particularly interesting devel- 
opments of the 3-inch testing stack was its 
perfect demonstration of back pressure. A 
Geco trap with 5-inch tail piece in its inlet 
end was connected to the 3-inch by 2-inch Y 
branch on the first floor, 13 feet 9 inches 
above the foot of the stack. The bathtub on 
the roof was then discharged. The back pres- 
sure within the stack was so great at the first 
floor trap that the trap water spouted out in 
gushes, some of the highest drops reaching 
the ceiling over 6 feet above. These gushes 
would break up like fountains into bubbles 
and drops, covering an area about 4 feet in 
diameter. A moderately successful photo- 
graph of this back pressure is shown in photo 
designated as No. 13. 

This outpouring of the trap contents into 
the room, or rather stairwell in this instance, 
was unaffected by the simultaneous siphonage 
of the fifth floor traps. 

Indeed any one had by one discharge of the 
bathtub the opportunity of seeing both the 
complete siphonage of the upper floor trap 
and the complete breaking of the seal of the 
lower floor trap by back pressure. I regret 



that the actual amount of this pressure was 
not measured. The amount of vacuum on the 
top floor was in excess of the capacity of the 
water column U tube gauge used, which was 
capable of registering 2% pounds. 

To compare the behavior of the vented % S 
trap under identically the same conditions, 
the Geco traps were removed from the 3-inch 
stack and the 3x2 branches plugged. A % S 
trap was then connected to the 2-inch by 1%- 
inch TY on the 2-inch vent stack on the first 
floor (as is usual in New York City practice) , 
and another % S trap connected to the 2-inch 
by 1^/2 -inch TY in the 2-inch continuous 
v;aste and vent connection on the fifth floor. 

The gate valves at the foot of the 2-inch 
vent stack on the first floor and in the 2-inch 
continuous waste and vent connection on the 
fifth floor were then opened and the bathtub 
on the roof discharged. The fifth floor trap 
seal was lowered by only 3/16-inch, leaving 
2-1/16-inch; the first floor trap was hardly 
disturbed, although a slight wave action was 
noticeable which removed about %-inch of 
its seal. 

^No tests were made at any time with the 
top opening of the 3-inch waste stack reduced 
in diameter. 

SUMMARY 

In summarizing I will adhere to the develop- 
ment of my subject, starting with the intro- 
duction of plumbing traps, reviewing the his- 
tory and present stage of trap development, 
referring to opinions of competent men about 
the Geco trap, and completing with the latest 
phases of the anti-syphon traps and Vz S 
vented trap tests in New York City. 

(A.) INTRODUCTION AND HISTORICAL 

DEVELOPMENT OF PLUMBING 

TRAPS 

The earliest records seeln to indicate the 
use of the "Bell" or "Stench" trap as early as 
1856 in this country, "improved" by a flap or 
check in 1862. The bent tube traps, D traps, 
Anti-D traps and similar forms appeared in 
about 1872 to 1875. 

Back-venting of traps seems to have been 
first agitated in 1875 to 1876 by the Brooklyn 
Board of Health and was recommended by 
Col. Waring in 1878. In 1879 unsuccessful 
attempts were made by a journeyman plumber 
to maintain patent claims on the back-venting 
system. 

The anti-siphon forms of traps with en- 



PLUMBING FIXTURE TRAPS 



67 



larged body similar to that used by the U. S. 
Housing Corporation was patented in 1873. 
The Geco trap was patented in 1910. 

The first serious attempt to supplant back- 
venting by anti-siphon traps began by Col. 
George E. Waring in 1880, two years after he 
had patented his anti-siphon tiap. Since then 
there has been much confusion about the sub- 
ject and many attempts have been made to be- 
cloud the issue by those interested, and to 
clarify it by independent engineers who were 
not patentees of traps. 

An investigation was made by Col. Waring 
on the subject for the National Board of 
Health. It appears to have contradicted the 
colonel's earlier statements about the necessity 
of back-venting, and the report was never pub- 
lished by the National Board of Health. 

In 1882, Messrs. Bowditch and Philbrick ex- 
perimented for the National Board of Health 
in an extensive and searching manner. These 
gentlemen recommended the use of back- 
venting. 

In 1882, S. S. Hellyer, of London, England, 
conducted a series of experiments. Although 
Mr. Hellyer was the patentee of the Anti-D 
trap, he advised the use of venting. 

In 1884, J. Pickering Putnam, of Boston, 
the patentee of the Sanitas trap, claims to have 
investigated the subject by experiments for the 
Boston City Board of Health. This board 
seems to have repudiated Mr. Putnam's report 
because of self interest and because of the re- 
fusal of Messrs. Bowditch and Philbrick to co- 
operate with him. Mr. Putnam's report was 
very strongly in favor of anti-siphon traps 
and the omission of back-venting. 

In 1885 the Master Plumbers' Association 
of Boston conducted experiments of their own 
in Worcester, Mass., under the supervision of 
its chairman, J. O. Sisson. Its findings favored 
the use of venting. 

About 1884, Dr. Chas. F. Chandler, then 
president of the New York City Board of 
Health, and later Professor of Industrial Chem- 
istry at Columbia University, conducted ex- 
periments in New York City, and on their 
strength enforced the plumbing regulations 
making the individual venting of fixture traps 
obligatory. Dr. Chandler stated publicly that 
the forced introduction of an unvented pat- 
ented anti-siphon trap would be a crime. 

In 1886, J. Pickering Putnam installed an 
experimental testing apparatus at the Massa- 
chusetts Institute of Technology. The appa- 



ratus, as illustrated in his book, shows that 
the trap vent connections were made on the 
house side of the trap under test and other 
irregularities which condemn the test and ita 
results as being either incompetent or unfair. 

In 1886, Glen Brown, of Washington, was 
asked to investigate and report on the use of 
anti-siplion traps versus % S vented traps to 
the U. S. Navy Department. Mr. Brown 
strongly favored venting. 

In 1906 tests of anti-siphon traps were made 
under the supervision of the Chicago Board of 
Health, resulting in the compulsory venting 
of traps. 

Tests were made in Washington, D. C, by 
the oflBce of the Engineering Commission of 
the District of Columbia, on the basis of which 
venting was made compulsory in that district. 

Additional tests were made by the Depart- 
ments of Building in Davenport, Iowa; Elmira, 
N. Y., and Wilkes-Barre, Pa., resulting un- 
favorably to the use of unvented anti-siphon 
traps. 

The cities of Richmond, Va.; Rochester, 
N. Y., and Holyoke and Springfield, Mass., 
reported that tests were made and that the 
use of unvented anti-siphon traps has been 
permitted in these cities since that time. 

It is reported that experiments were also 
made by H. J. Luff, the patentee of an anti- 
siphon trap, at the Case School of Applied 
Science at Cleveland, Ohio; that these tests 
were not, however, carried on under ordinary 
operating conditions; they are therefore in- 
competent. 

T. N. Thomson, instructor of plumbing at 
the International Correspondence School, 
Scranton, Pa., reported on observations of 
actual conditions where traps were forced by 
back pressure because of the absence of 
venting. 

In 1919 tests were made in Bridgeport, 
Conn., at the direction of the U. S. Housing 
Corporation by a committee of five, consisting 
of three engineers, a plumbing contractor and 
a sanitary inspector. These tests were un- 
fortunately left incomplete. 

A survey of these investigations and tests 
shows that those made by disinterested and 
competent men invariably resulted in reports 
favoring the use of venting and the elimina- 
tion of unvented anti-siphon traps, except in 
the case of Rochester, Holyoke, Springfield 
and Richmond, Va. In these instances the 
apparatus uaed for testing was not an actual 



68 



PLUMBING FIXTURE TRAPS 



plumbing installation, but differed therefrom 
so completely that it became merely a labora- 
tory apparatus which undoubtedly was capa- 
ble of determining the relative siphonage re- 
sisting qualities of anti-siphon traps as com- 
pared with each other, but which was not fit 
to determine the advisability of the use of anti- 
siphon traps in place of vented V2 S traps. 

The reports on tests which favored the use 
of anti-siphon traps were made by Col. War- 
ing, J. Pickering Putnam and H. J. Luff. All 
three of these men were patentees of anti- 
siphon traps. 

Tests which formed the basis of reports 
favoring venting systems were made by Bow- 
ditch and Philbrick, sanitary engineers of Bos- 
ton, Mass.; S. S. Hellyer, sanitary engineer, 
London, England; Glen Brown, architect, 
Washington, D. C. ; Dr. Chas. F. , Chandler, 
president, New York City Board of Health and 
professor of Columbia University; and the 
Building or Health Departments or similar 
official bodies of the following cities: Chicago, 
m.; Davenport, Iowa; Washington, D. C. ; 
Elmira, N. Y., and Wilkes-Barre, Pa. In ad- 
dition thereto the Master Plumbers' Associa- 
tion of Boston reported favorably on indi- 
vidual venting. 

(B.) PRESENT STAGE OF TRAP 
DEVELOPMENT 

By means of a questionnaire sent to the chief 
plumbing inspectors of 185 cities in this coun- 
try outside of New York City, which were re- 
corded in the "Standard Diary" as having in 
1916 an estimated population of over 35,000 
inhabitants, information was elicited about the 
present trap situation in cities, in number 107, 
having a total population of about 23,000,000. 
The total population of the cities to which the 
questionnaire was sent was about 30,000,000, 
so that the replies to the questionnaire cover 
58 per cent, of the number of the cities and 
77 per cent, of their population. 

Analyses of the returns show the following 
facts: 

1. In 81 per cent, of the number, and in 
84 per cent, of the population of the cities, 
unvented anti-siphon traps are not permitted 
for general use in new buildings. 

2. In about 40 per cent, of this number and 
about 24 per cent, of this population, anti- 
siphon traps are not allowed, whether vented 
or unvented, for general use in new buildings. 

3. In about 4 per cent, of the number, and 



in about 4 per cent, of the population of the 
cities from which information is available, are 
unvented siphon traps permitted for general 
use, but with decided limitations. 

4. In about 17 per cent, of the number, and 
in about 11 per cent, of the population of the 
cities, is general use of the unvented anti- 
siphon traps permitted. 

5. In these cities, in which unvented anti- 
siphon traps are permitted, the maximum al- 
lowable distances from the traps to the soil 
or waste stacks vary from 18 inches to 25 
feet; in the case of Macon, Ga., there is no 
extreme limit. 

6. In not a single city, except New York, 
is only one anti-siphon trap reported approved 
to the exclusion of all others. 

7. In not a single city is the 1%-inch or 2- 
inch Geco trap approved- by the Board of 
Standards and Appeals of New York City, 
reported as approved or in use. 

(C.) OPINIONS OF THE GECO TRAP 

An actual size blueprint of the cross section 
of the Geco trap was sent by me to a number 
of the chief plumbing inspectors of various 
leading cities, together with a letter request- 
ing them to express their opinions on this trap 
and asking their permission to publish their 
opinions, which permission was given in all 
cases except that request was made by a few 
to withhold their names. 

Twenty-six such replies show that the offi- 
cials of only three cities, with a total popula- 
tion of only 280,000, are apparently not op- 
posed to the Geco trap without venting; in 
only two cities, with a total population of 430,- 
000, apparently not opposed to the Geco trap 
for emergency use without venting ; of six cities, 
with a total population of 930,000, not opposed 
to the general use of the Geco trap with vent- 
ing; but of twelve cities, with a total popula- 
tion of over 8,500,000, opposed to the use of 
the Geco trap whether vented or unvented. 

It is of especial interest to note that among 
the latter are Washington, Chicago, St. Louis, 
Philadelphia and Cleveland, and that more- 
over Rochester and Schenectady, both of which 
do permit certain forms of anti-siphon traps, 
are opposed to the Geco trap with or without 
venting; so is also Cincinnati, which permits a 
limited use of anti-siphon traps. Springfield, 
Massachusetts, which has tested and approved 
numerous anti-siphon traps without vents. 



PLUMBING FIXTURE TRAPS 



69 




No. 10.— The Geco Trap Ready for Testing 

in Building at 366 W. Broadway, 

New York City 

is also opposed to the Geco trap without 
venting. 

In addition to these opinions T. N. Thom- 
son, of Scranton, Pa., finds several flaws in 
the trap; Professor Chandler opposes its in- 
troduction. My own opinion of the trap per se, 
without any reference to the question of 
whether it should be vented or unvented, is 
that, while it has a pleasing exterior and prob- 
ably not an excessive depth of seal, it violates 
provisions 90, 100 and 112 of the New York 
City Plumbing Rules and Regulations as 
adopted by the superintendents of buildings, 
eflFective April 23, 1912, and as amended by 
the Board of Standards and Appeals, July 5, 
1917, and December 27, 1918, effective January 
27, 1919, in that it has a lower partition upon 
which the trap depends for its seal under cer- 
tain conditions, and in that it has three re- 
strictions in its diameter or cross-section areas, 
namely at the top of the inlet tube, at the bot- 
tom of the inlet tube and at the outlet tube. 

I consider that the trap offers greater resist- 
ance to the flow of liquids and thereby greater 
opportunity for fouling than a 1^/4 -inch S trap. 
I consider that its rough interior surfaces will 
stimulate fouling, and that under high rates of 



flow there will be circular eddies within the 
trap tending to wrap hair, lint and other 
fibrous materials into balls and to reject them 
together with other suspended substances into 
the contracted inlet. 

I estimate from the ratio of the wetted areas 
to the trap contents that during the same rest 
periods aiid with water containing the same 
percentage of grease, the thickness of grease 
congealed on the walls of the 1%-inch Geco 
trap will be twice as thick as that deposited 
on the walls of the 1%-inch P trap. Since 
the velocity of flow through the P trap is 
about eight times as great as it is through the 
enlarged body of the Geco trap, there exists a 
considerably greater tendency for the passing 
water to tear away any grease collected on the 




No. 11. — The One Half S Back Vented Trap 

Ready for Testing in Building at 366 

West Broadway, New York City 



70 



PLUMBING FIXTURE TRAPS 




No. 12. — Showing the Apparatus Installed on the Roof of the Building at 366 W. Broadway, 
New York City, Utilized for Trap Testing Purposes 



walls of the P trap, while it remains attached 
to the walls of the Geco trap. 

(D.) TESTS OF VENTED Va S AND ANTI- 
SIPHON TRAPS IN NEW YORK CITY 

1. Board of Standards and Appeals Tests of 
Geco Traps at 30 City Hall Place 

These tests were made informally in the 
afternoon of August 13, 1918, and were wit- 
nessed by me. They were similar to those 
performed at Rochester, N. Y.; Springfield 
and Holyoke, Mass., and like these, were en- 
tirely devoid of any semblance to conditions 
prevailing in actual plumbing. 

As laboratory tests they would answer per- 
haps to compare the siphonage resisting power 
of anti-siphon traps; but as a means of deter- 
mining their reliability in actual plumbing 
practice, these tests were a farce as I saw 
them; no attempt was made to gauge the rate 
of flow; the flushing periods were not even 
timed by a watch. 

The use of a 1%-inch waste pipe is against 



the rules of the plumbing code, which pre- 
scribes not less than a 2-inch pipe. The pipe 
was closed at the top and open at the bottom 
without connection to the sewer, and thereby 
created conditions essentially different from 
those encountered in a plumbing system. 

It is inconceivable to the trained engineer 
that the greatest city in the world should have 
attempted to determine the reliability of an 
apparatus which is intended to protect man- 
kind against foul air produced from the decom- 
position of its own waste products by means 
of a testing apparatus erected on a fire escape 
entirely disconnected from a plumbing system, 
completely diflferent from actual plumbing 
practice, not even complying with the plumb- 
ing code, and operated in a manner similar to 
that used by children playing with toys. 

2. Board of Standards and Appeals in the 
Hallenheck Building 

This test was made on May 1, 1919. It was 
not witnessed by me. A description of it was 



PLUMBING FIXTURE TRAPS 



71 




No. 13.— Photo Showing Results of Back 
Pressure in Geco Trap Test in West 
Broadway Building, New York City 

given in the June 4, 1919, issue of the 
American Architect by Edward F. Hammel, 
formerly engineer of the board. I inspected 
the plumbing in the building on the following 
day and had photographs made of certain por- 
tions of it. These tests were incompetent in 
the following respects: 

a. The only Geco trap under test for siphon- 
age by water flushing through its waste stack 
was placed on the first floor, where practically 
no siphonic action occurs, but where the at- 
mospheric pressure within the stack is almost 
always positive, resulting in blowing the trap 
rather than siphoning it. 

b. The Geco traps claimed to have been 
placed on the waste pipes from flush tanks on 
the upper floors could not have been siphoned, 
because they would refill from the trickle when 
the flush tank was practically empty. 

c. The plumbing system was fitted in nu- 
merous places with unvented V2 S basin traps 
which would be immediately siphoned by 



flushes into the stack and would then act as 
vents, promptly relieving any vacuum which 
might have existed in the upper reaches of 
the stack. 

d. The connections from the flush tanks to 
the lead bends were made by putty joints, 
which are subject to air leakages. 

My opinion is, therefore^ that these tests 
made by the Board of Standards and Appeals 
at the Hallenbeck Building showed a com- 
plete lack of appreciation on the part of those 
responsible for them of the fundamental es- 
sentials necessary for such tests. 

3. Tests at 366 West Broadway 
a. 4>-Inch Stack 

These tests were comparative tests between 
10 different types of unvented anti-siphon 
traps and the vented V2 S trap. The anti- 
siphon traps held from about 4 to 6 times 
as much water as the % S trap and their 
cross sectional area is about 2 to 5 times as 
great. Both of these qualities increase the 
tendency of fouling materially. 

The traps were tested by flushing from a 
roof tank into the 4-inch stack, at the rates of 
50, 100, 150 and 300 gallons per minute. They 
were also tested under varying conditions of 
soil stack openings above the roof, that is, 4- 
inch, 1-5/16-inch, 1-inch and 9/16-inch. Dur- 
ing these tests the Geco trap seal was broken 
completely 6 times; the U. S. Housing Cor- 
poration trap seal 9 times; the V2 S vented 
trap seal only once, and that under the most 
severe conditions purposely imposed to de- 
termine the limit of resistance of the vented 
% S trap. 

The Geco trap seal was destroyed with 150 
gallons per minute flushing rate and a soil 
pipe opening of 1-5/16-inch, while the U. S. 
Housing Corporation trap seal yielded com- 
pletely under the still less severe condition of 
a 4-inch stack opening and 100 gallons per 
minute flushing rate. Under these same con- 
ditions the vented % S trap retained 1%-inch 
seal. 

Other anti-siphon traps behaved similarly to 
the Geco and U. S. Housing Corporation trap. 
The flushing rate, 150 gallons per minute, rep- 
resents the simultaneous discharge rate of only 
2 siphon- jet or siphon-action water closets, 
supplied with the usual type of flush valves. 

The decrease in diameter of a 4-inch soil 
pipe to an opening 1-5/16-inch above the roof 



72 



PLUMBING FIXTURE TRAPS 



may reasonably be expected after extended 
cold weather periods. It must be borne in 
mind also that the traps tested were thoroughly 
clean and would probably have been siphoned 
much more easily had they been fouled by 
usage. 

All plumbing work including fixture traps 
should possess, similar to all engineering con- 
struction, a factor of safety. There is no fac- 
tor of safety in the Geco trap. Since the 
standard fixture trap the country over has been 
the %-S vented trap no other trap can be 
offered in substitution successfully which does 
not have at least as strong siphonage resist- 
ing power as the standard which it is intended 
to replace. 

The seal of the Geco trap exceeds that of 
the V2 S trap tested by about 90 per cent. 
For a comparative test a % S trap of equal 
seal to the Geco trap should have been used. 
No reason exists why the V2 S trap should not 
have a 4^-inch seal instead of a 2^-inch seal. 
Under such conditions its strength of with- 
standing siphonage would have been greatly 
increased. 

Calculations and graphic determinations 
were made to determine the percentage of seal 
loss from each trap in order to compare the 
siphonage resisting qualities of the various 
traps including the V2 S trap inch for inch of 
water seal. These graphic illustrations are 
striking and convincing proof of the inherent 
weakness of anti-siphon traps as compared to 
the inherent strength of vented V2 S traps. 

Tests of the atmospheric pressures within 
the 4-inch soil pipe stack due to the plumbing 
fixture discharges indicated variations of from 
30 to 40 ounces positive to about an equal 
amount negative, that is, total variations of 
from 4 to 5 pounds at different points of the 
stack. It seems impossible that any anti- 
siphon trap no matter how well designed could 
possibly adapt itself with its small water col- 
umn to any conditions within such wide limits, 
without the use of special and effective means 
for furnishing or removing air as required by 
the variations of the atmospheric pressures 
within the plumbing system. 

There is no doubt but that traps can be con- 
structed of sufficient size to accomplish this 
result, but they would have to be so out of 
proportion that they would be small cesspools. 

b. 3-lnch Stack 
The traps connected to this stack were 



tested to determine the minimum rate of flush 
required to siphon them without any decrease 
in the size of the stack opening. It was found 
that the Geco trap seal was completely broken 
by a flushing rate of 76 gallons per minute, 
with a total discharge of 53 gallons from a 
barrel; or it could be broken completely by 
three 5-second flushes vdth an average flush- 
ing rate of 111 gallons per minute. 

The Geco trap seal was also destroyed en- 
tirely by discharging 35 gallons of water from 











^^B ''^^ 



Showing the Apparatus Installed for the New 
York City Board of Standards and Ap- 
peals on the Fire Escape of 30 City 
Hall Place Building, For Its Test 
August IS, 1918 



PLUMBING FIXTURE TRAPS 



73 



the bathtub on the floor above through a 2- 
inch trapped waste pipe into the 3-inch stack. 
This discharge was at the rate (average) of 
75 gallons per minute. 

The vented % S trap was tested under the 
identical conditions as the Geco trap and 
other anti-siphon traps, but its seal remained 
at 2-1/16-inch and could not be lowered be- 
low this point in any of the tests. 

The 3-inch stack was also used to determine 
the effect of back pressure, if any, on an anti- 
siphon trap located on the first floor when the 
bathtub was discharged on the sixth floor. 
The back pressure was developed to such an 
extent that it erupted the water from the first 
floor trap to the ceiling, 6 feet above, covering 
an area of about 4 feet in diameter on the 
floor and leaving the trap seal destroyed. 

The discharge of sewage atomized in this 
manner by compressed air into a room is an 
extremely dangerous occurrence, in my opin- 
ion more so than the siphonage of a trap. I 
do not believe that any anti-siphon trap can 
be made without mechanical features or with- 
out disproportionate size which will effectively 
withstand such back pressures. 

The vented % S trap exposed to the same 



conditions of back pressure indicated merely 
a slight wave action of its seal, losing only 
about %-inch in depth of seal. 

In conclusion, I wish to say that any trap 
tests made on clean traps must always lay due 
stress on that fact. Nothing has been done so 
far as I know by other investigators to deter- 
mine the ratio between the siphonage resist- 
ing power of clean anti-siphon traps and of 
those fouled to such a degree that they are 
filled with sediment or grease with the excep- 
tion of a slight passageway. • 

When these are made, a great deal more 
light wiU be shed on this subject, but I am 
satisfied that the tests directed by me with 
clean anti-siphon traps gave conclusive evi- 
dence of their insufficiency and inherent weak- 
ness and lack of resiliency to condemn them 
for general use in high grade plumbing work. 

It would be negligent of me were I to fail 
in expressing my gratitude to those officials 
of other cities and to those brother engineers, 
who gave expression to their views, and who 
so kindly furnished me with replies to my 
questionnaire, with copies of their cities* 
plumbing codes and descriptions of their tests. 



74 



#NBi4 



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Bas/a/ 






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J? /loo/?. 




Plumbing diagram of typica ,three- 
story apartment house. Heavy solid 
lines show the soil, waste, and vent 
pipes required by the New York City 
Plumbing Code, if anti-siphon traps 
are installed for all of the fixtures 
(exclusive of water closets). The 
dotted lines show additional vent 
pipes required if ^i-S vented traps 
are used. 



PLUMBING FIXTURE TRAPS 75 

THE ECONOMIC SIDE OF THE PROBLEM 



IT was intended to make this book cover 
only the technical or engineering proper- 
ties of traps, but so much stress has been 
laid recently on the economic side of the anti- 
siphon traps, and so many statements have 
been made and are now being made in regard 
to the reduction of the cost of plumbing in- 
stallations by the use of unvented anti-siphon 
traps, that it is of general interest to all con- 
cerned to clear up the economic question. 

Perhaps the most recent example of such 
statements in my experience occurred during 
May, 1921, where testimony was given by a 
builder before Mr. Samuel Untermyer, chief 
counsel for the Lockwood (New York State) 
Housing Investigating Committee, to the effect 
that the installation of approved anti-siphon 
"Geco" traps in a certain New York City build- 
ing would have reduced the cost of a plumbing 
installation about 50 per cent below that of a 
vented ^-S trap system. This assertion was 
widely published in the daily press and at- 
tracted large attention, especially since the 
usual story of robbery by the "Plumbing Ring'* 
was interwoven in the press reports. 

That the witness '^as thoroughly misin- 
formed on the subject of his testimony, will 
be clear to any one who reflects for a moment 
on the fact that the cost of the plumbing 
fixtures — that is, the water closets, urinals, 
slop sinks, wash basins, bathtubs, kitchen 
sinks, and wash tubs; of the hot and cold 
water supply pipes and fittings, and of the soil 
and waste pipe systems is entirely unaffected 
by the use or absence of anti-siphon traps, and 
remains the same, whether these or ^-S 
traps with vents are used. The total cost of 
these items is from 90 to 98 per cent, of the 
cost of the entire plumbing job. 

Furthermore, if the witness had been quali- 
fied to testify or had been properly informed, 
he would have appreciated that under the 
New York City Plumbing Code requirements, 
all water closets must be backvented, there 
being no approved deep-seal fixtures of this- 
kind on the market. He would also have 
known that a separate vent stack would have to 
be installed, and that therefore the only actual 
saving by the use of anti-siphon traps would 
be the short vent branches from the fixtures 
(other than water closets) to the vent stack. 

In order to satisfy myself on the real econ- 
omy, if any, of anti-siphon traps as compared 



with i/^-S vented traps, I prepared a plumbing 
diagram of a typical three-story apartment 
house, reproduced herewith, which shows in 
full lines the soil, waste, and vent pipes re- 
quired by the New York City Plumbing Code, 
if the approved "Geco" anti-siphon trap is 
installed for all of the fixtures (exclusive of 
the water closets) , and in dotted lines the ad- 
ditional vent pipes required, if the Vz-S vented 
traps are used. I submitted this diagram to 
three responsible New York master plumbers 
with the request that they estimate the costs 
of the 1/4 -S traps and their vent branches as 
shown in dotted lines, and also of the "Geco" 
anti-siphon traps without vents, as permissible 
under the New York City Code. I asked them 
further to consult with each other, and to 
present to me, if possible, joint estimates 
which they would consider fair. These esti- 
mates were as follows: 

Unvented "Geco" Traps. 

e—lVz" Geco Traps @ $7.. $42.00 
3_2" Geco Traps @ $11... 33.00 



Total Cost $75.00 

Plus 10% Profit 7.50 



$82.50 



Vented Yz-S Traps. 
24'— 11/2" Galv. Pipe @ $.18. . $4.32 

9'—iy2" Galv. Pipe Mall. Fit- 
tings @ $.30.... 2.70 

e—lVz" Brass V^-S Trajps @ 

$1.30 7.80 

■3—2" Brass Vz-S Traps @ 

$2.50 7.50 

1 Day Labor 10.00 

Total Cost $32.32 

Plus 10% Profit 3.23 



$35.55 



Excess Cost of Unvented 
"Geco" Traps Over Vented 
Vz'S Traps $46.95 

The estimates, it will be observed, show that 
the actual cost to the owner, including a 10 
per cent plumbers' profit, which I asked to 
be included, of the vented ^-S traps, is about 
$50.00 cheaper than of the "Geco" unvented 
traps. I believe that the estimates are in- 
tended to be proper and are deserving of con- 



76 



PLUMBING FIXTURE TRAPS 



fidence. Assuming, however, that the labor 
item of the vented ^/^-S traps had been 200 
per cent underestimated, there would still 
remain a balance of $25.00 in favor of the 
vented ^-S traps. 

An analysis of the estimates of cost made 
by the plumbing contractors, indicates that the 
materials required are correctly inventoried 
and priced, and that the labor to be performed 
consists of measuring and cutting 14 pieces 
of 1^" galvanized iron pipe to lengths not 
exceeding 3 feet; of cutting 28 1^" pipe 
threads, and of installing 14 pieces of 1^" 
pipe and nine 1^" fittings. The measuring 
and cutting should reasonably consume not 
over 1/4, hour each, or 3^ hours total; the 
cutting of 28 threads not over 1/7 hour each 
or 4 hours total; the installation of 14 pieces 
and nine fittings not over 1/3 hour each or 
8 hours total. My own estimate of the total 
labor required would, therefore, be 15^ hours, 
or say 2 days, instead of 1 day, or $20.00 in- 
stead of $10.00; but even under this condi- 
tion the ^-S vented traps are about $36.00 
cheaper than the unvented "Geco" anti-siphon 
traps. 

If the number of floors were increased, or 
the number of apartments per floor multi- 
plied, each requiring a similar typical plumb- 
ing installation, this difference would, of 
course, become correspondingly greater. It 
is evident that the greater cost of the un- 
vented "Geco" anti-siphon traps is largely 
due to the high cost of the traps themselves. 



Seven dollars for a lYz" and $11.00 for a 2" 
trap are big prices which seem unwarranted 
except on the ground of patent or other fees. 

From the representative example given, it 
is fair to conclude that the much-voiced opin- 
ion on the invariably lesser cost of unvented 
anti-siphon traps is not based on actual facts; 
there are, no doubt, certain individual cases, 
especially in alteration work or in small dwell- 
ings in which this opinion will be found to 
be true, but the evidence shows, particularly 
where the plumbing is condensed near the 
vertical stacks and where toilet or bathrooms 
are located repeatedly alike and directly over 
each other, as is usually the case in apart- 
ment buildings, hotels, and office buildings, that 
the V^-S vented traps are as cheap and per- 
haps cheaper than unvented expensive anti- 
siphon traps. It must be borne in mind in 
this connection also, that patented articles 
are unlimited in price and not subject to com- 
petition, especially where, as at present in 
New York City, only one such article is ap- 
proved for use. 

The chief item of cost in a back-venting sys- 
tem is involved in the venting of water 
closets, which are not made with anti-siphon 
traps ; these must be back vented in any event, 
according to most of the plumbing codes. The 
.only additional vent pipes required, there- 
fore, for the other plumbing fixtures, consist 
of the short 1^/^" and 2" branches which con- 
nect the individual traps to the main vent stack 
or to the water-closet vent branch. 



INDEX 



AIR Circulation 2 

Pressures 5, 9, 49 

Akron, Ohio 18 

Albany, N. Y ...AS 

Allentown, Pa 18 

Altoona, Pa 18 

American Inst, of Arch'ts 9 

Amsterdam, N. Y. 17 

Anderson, Adolph 20 

Anti-Siphon Traps, 

Patents on 1, 2 

Adjustment to air pressure variations ... .49 
See Traps, Anti-siphon 

Atlantic City, N. J 17 

Atlanta, Ga 18 

Auburn, N. Y 18 

Augusta, Ga 17 

Avery, F, L 15 

BACK Venting, Patent Claims on 2, 3 

Ball, Chas. S 16 

Baltimore, Md 17 

Barhydt, D. P 2 

Bayonne, N. J 18 

Bay City, Mich 18, 19, 21 

Bell Trap 1 

Bennor, Joseph 2 

Berkeley, Cal 18 

Binghamton, N. Y 17 

Birmingham, Ala 18 

Boston Board of Health 6, 7, 8, 67 

Boston, Mass 17 

Boston Master Plumbers' 

Association 8, 67, 68 

Bowers, B. P 2 

Bowditch, Ernest W 5, 10, 67, 68 

Brandeis, Ludwig 2 

Bridgeport, Conn 16, 18, 67 

Brockton, Mass 18 

Brooklyn Board of Health 66 

Browne, Dr. J. Mills 9 

Brown, Glenn 9, 10, 67, 68 

BuflFalo, N. Y 17 

Burlington, Vt 18 

Bush, Charles H 1 

Butte, Mont 16 

CAMBRIDGE, Mass 18 

Camden, N. J 17 

Campbell, John 20 

Canton, Ohio 18 

Carson, Alfred 1 



Cedar Rapids, la 18 

Chandler, Dr. Chas. F 10, 22, 67, 68, 69 

Charleston, S. C 17 

Charlotte, N. C 17 

Chattanooga, Tenn 17 

Chelsea, Mass 18 

Chester Pa 17 

Chicago, 111! . . . .* 11, 18, 19, 21, 22, 67, 68 

Cincinnati, Ohio 18, 20 21 22 68 

Clafify, Thos. J 19 

Cleveland, Ohio 12, 18, 20, 21, 22, 68 

Cloutier, F. W 20 

Cody, George 2 

Columbus, Ohio 18 

Connolly, F. W 20 

Covington, Ky 18 

Cudell, Frank E 2 

Cudell Trap 60 

D-TRAP 1 

Dallas, Tex 17 

Davenport, la 12, 18, 67, 68 

Dayton, Ohio 18, 19, 21 

Dead Line of Traps 37, 38 

Decatur, 111 18 

Des Moines, 111 18 

Denver, Colo 18 

Detroit, Mich 18 

Doherty, Patrick W. 2 

Dowd, J. F 20 

Du Bois, Frederick N 2 

Dubuque, la 17 

Duluth, Minn 18, 20, 21 

DuMond, Frank 13 

Drum Trap 53, 63 

EAST Orange, N. J 17 

East St. Louis, 111 18 

Economic Side of Anti-Siphon Traps 75 

Elmira, N. Y 12, 18, 20, 21, 67, 68 

Elizabeth, N. J 18 

El Paso, Tex 17 

Erie, Pa 17 

Evansville, Ind 17 

Everett, Wash 17 

Everett, Mass 18 

Existing Conditions in U. S 16, 17 

FALL River, Mass 17 

Femco Trap 51, 61 

Fitchburg, Mass 17 

Fisher, Edwin A 13 



80 



PLUMBING FIXTURE TRAPS 



Fladd, Frederick E 13 

Flap Valve 1 

Flint, Mich 18 

Flyun, Hon. Wm. J 26 

Fort Worth, Tex 17 

GALLOWAY, W. T 19 

Galveston, Tex 18 

Geco Trap, 

Opinions of Plumbing Officials 

17, 19, 20, 21, 22, 23, 68, 69 

Description . . . . 22, 23, 24, 25, 69 

Fouling 22, 23, 24, 25 

Tests by the N. Y. City Board of Stand- 
ards & Appeals .22-23, 25-35, 70-72 

Tests under direction of Author at 366 
West Broadway, New^ York City, 

General description 36-38 

Tests on V Stack 36-50, 54, 71 

Tests on 3" Stack . . . .49-52, 54, 66, 72, 73 
Non-compliance with N. Y. City Plumb- 
ing Code 69 

Gerhard, Dr. Wm. Paul 3-5, 16 

Grand Rapids, Mich 17 

Griffen, Peter P 19 

HALLGRING, Chas. A 21 

Hamilton, Ohio 17 

Hammel, Edward F 26, 33-35, 71 

Harrisburg, Pa 17 

Hartford, Conn 18 

Hatfield, W. E 1 

Haverhill, Mass 17 

Hellyer, Samuel S 2, 4, 5, 67, 68 

Historical 1-16 

Hoboken, N. J 17 

Holyoke, Mass 15, 17, 18, 21, 67, 70 

Houston, Tex 18 

Hosford, Leonard D 2 

Hoyt, Wm. E 8 

Huntington, W. Va 17 

Hydric Trap 57 

Hylan, Hon. John F 26 

IDEAL Mfg. Co 2 

Indianapolis, Ind 18 

International Correspondence 

School 11, 13, 21, 67 

JACKLEY, Wm. J 19 

Jackson, Mich 17 

Jacksonville, Fla 18 

Jamestown, N. Y 18, 20, 21 

Jersey City, N. J 18 

Johnstown, Pa 18 

Joliet, 111 17 



KALAMAZOO, Mich 17 

Kansas City, Kan 18 

Kansas City, Mo 18, 19, 21 

Kimley, J. J .19 

Knoxville, Tenn 17 

Kroul, Edgar E 12, 20 

LA FORCE, E. F 19 

Lancaster, Pa 17 

Landers, Thos. M 11, 19 

Lansing, Mich 17 

Lawrence, Mass , 18 

Leo, Hon. John P 26 

Lexington, Ky 17 

Lincoln, Neb .18 

Longfellow, Professor 1 

Lorain, Ohio 18 

Los Angeles, Cal 18 

Louisville, Ky 18 

Lowell, Mass 18 

Luff, Henry J 2, 67, 68 

Lynn, Mass .18 

MACON, Ga 17, 18, 68 

Maiden, Mass 18 

Manchester, N. H .17 

Master Plumbers' Association of 

Greater New York 26 

Mass. Institute of Technology 8, 67 

McCarthy, J. W 16 

McCloskey, John 2 

McGonegal, A. R 12, 19 

McGuckin, Henry 2 

Mclntire, J. N 2 

McKeesport, Pa 17 

Meinert, Otto 12 

Memphis, Tenn 18 

Meyer, Henry C 6, 7 

Miami, Fla 18 

Milwaukee, Wis 18 

Minneapolis, Minn 18, 20, 21 

Mobile, Ala. 17 

Monaghan, Joseph F 13 

Monarch Trap 59 

Morgan, Thos. A 13 

Mount Vernon, N. Y 17 

Munziger, Louis 2 

Muskogee, Okla 18 

NASHVILLE, Tenn 18 

National Board of Health, 

Trap Tests for 3-6, 10, 67 

Nelson, R. E .17 

Newark, N. J 18, 21 

New Bedford, Mass 18 

New Britain, Conn 18 



PLUMBING FIXTURE TRAPS 



81 



New Castle, Pa * 17 

New Orleans, La 18 

New Rochelle, N. Y 17 

Newton, Albert S 2 

Newton, Mass 18 

New York City — 

Dept. of Health 10 

Board of Standards & Appeals .. 17, 68-70, 72 

Use of Anti-siphon traps in 17 

Niagara Falls, N. Y 18 

Norfolk, Va 17 

OAKLAND, Cal 18 

O'Kane, J. Alfred .13 

Oklahoma City, Okla 17 

Omaha, Neb 18, 19, 21 

Oshkosh, Wis 17 

PATENTS on Traps 1, 2, 3 

Paterson, N. J 18, 20 

Pasadena, Cal 18, 21 

Passaic, N. J , 17 

Pawtucket, R. 1 17 

Peoria, 111 17 

Perth Amboy, N. J 17 

Philadelphia, Pa .18, 20, 21, 22, 68 

Philbrick, Edward S 3, 6, 10, 67, 68 

Pittsburgh Pa 18 

Pittsfield, Mass 18 

Portland, Ore. 18 

Portland, Me 17 

Portsmouth, Va 17 

Providence, R. 1 17 

Providence Steam Trap Co 11 

Pueblo, Colo 18 

Putnam, J. Pickering 2, 6, 7, 8, 10, 67-68 

QUINCY, Mass .18, 19, 21 

<)uincy. 111 18 

RACINE Wis .18 

Rainger, Chas. A 12, 20 

Reading, Pa 17 

Reed, Winfield S 20 

Rice, Frederick L 6 

Richmond, Va 11, 18, 19, 21, 67 

Roanoke, Va 17 

Rochester, N. Y.. . .11, 13, 18, 20, 21, 67, 68, 70 
Rockford, 111 18 

S, V2 S, P, or bent pipe trap 1, 53-63 

Saaco Trap 2, 39, 41-43, 47-50, 52, 62, 67 

Sacramento, Cal 17 

Saginaw, Mich 17 

Salem, Mass 18, 19 

Salt Lake City, Utah .17, 18, 21 



San Antonio, Tex 18 

San Diego, Cal 18 

San Francisco, Cal 18 

Sanitary Co. of America 2, 41 

Sanitas Trap 56 

Sanito Trap 55 

San Jose, Cal .18 

Savannah, Ga 18 

Schenectady, N. Y 18, 19, 21, 22, 68 

Scranton, Pa 13, 17, 21 

Seattle, Wash 18 

Shaver, Arthur C 21 

Sioux City, la 17 

Sisson, J. 8, 67 

Smith, John F 20 

Smith, Thos 1 

Somerville, Mass 17 

South Bend, Ind 17 

Spokane, Wash 18 

Springfield, 111 17 

Springfield, Mass 15, 18, 21, 22, 67, 68, 70 

Springfield, Mo 18 

Springfield, Ohio 17 

inU. S 16-18 

St. Joseph, Mo 17 

St. Louis, Mo 18, 19, 21, 22, 68 

St. Paul, Minn 17 

Summary 66-73 inclusive 

Superior, Wis 17 

Syracuse, N. Y 17 

TACOMA, Wash. 18 

Tampa, Fla 18 

Taunton, Mass 17 

Terre Haute, Ind 18 

Thompson, Nelson S 16 

Thomson, T. N 11, 21, 67, 69 

Toledo, Ohio 18 

Topeka, Kan 17 

Tower, Frank W 11, 15, 16 

Trenton, N. J 18 

Troy, N. Y 18 

Traps — 

Anti-siphon, 

Adee 5 

American Pin Co 18 

American Sanitary Mfg. Co 18 

Anti-D 5, 66, 67 

Anti-D, Narrow Band 5 

Bell or Stench 1, 66 

Bennor 8 

Boosey 18 

Bottle 6, 8 

Bowers 3, 5, 8, 12, 15, 18 

Buckeye Seneca Sanitary Co 14, 18 

Centrifugal 15, 18 



82 



PLUMBING FIXTURE TRAPS 



Traps (continued) 

Clark 18 

Clean Sweep 15, 18 

Clow 11, 18 

Cody 14 

Connolly 11, 15, 16 

Cudell 2, 5, 8, 14, 15, 18, 39, 47, 48, 60 

Dome 11, 15, 16 

Drum 11, 15, 16, 18, 39, 53, 63 

DuMond-Baker 18 

Eclipse 5 

Economic Side of Anti-Siphon Traps 75 

Elgin Brass Co 18 

Femco 11, 15,16,39, 51,61 

Garland 3 

Geco 11, 12, 19, 22, 23, 24, 39, 67 

Hajoca 11, 14, 15, 16, 18 

Helmet 5 

H. M 14 

Hydric 39, 45, 57 

Ideal 18 

Imco 11, 15, 16, 18 

King 15 

Marvel 18 

McAuliffe 11, 15, 16, 18 

Mechanical 1-4, 9, 18 

Monarch 11, 14, 15, 16, 18, 39, 47, 59 

Newton 11, 15, 16, 18 

Nicholson Mercury Seal 3 

Novis 11, 18 

Oldfield 18 

Paragon 3, 4, 11, 14, 15, 16, 18 

Positive 11, 15, 16, 18 

Pot 6 

Public Safety 14, 18 

Radcliffe 11, 15, 16 

Rochester Lead Works 14 

Round 8 

Saaco 39, 41-43, 47-50, 52 

Sanitas 8, 11, 15, 16, 18, 39, 44, 56 

Sanito 18, 39, 43, 55 

Seneca 18 

Shiler ..14, 18 

Simplex 18 

Turner 14 

W. & W. Selo 14, 18 

Whiteford 11, 18 

Wolff Mfg. Co 11, 14, 18 

Wolverine 11, 14, 16, 18, 39, 46, 58 

Woodward, McAuliffe, Wanger 18 

Back-pressure on 5, 9, 10, 26, 33, 

34, 49, 66, 71, 72 
Comparison of Siphonage resisting quali- 
ties of vented V2 S traps with un- 
vented 
Cudell trap 60 



Traps (continued) 

Drum trap 65 

Geco trap 1-43, 47-52, 54, 71 

Femco trap .61 

Hydric trap 57 

Monarch trap 59 

Saaco trap 41-43, 48-50, 62, 71 

Sanitas trap 56 

Sanito trap 5S 

U. S. Housing Corp. trap 

41-43, 48-50, 62, 71 

Wolverine trap 52 

Traps, Comparative Cost 75 

Traps, Factor of Safety 46, 72 

Traps, Fouling of . .6, 10, 23, 24, 39, 46, 69, 7^ 
Traps, Tests of 

Altoona, Pa 11 

Akron, Ohio 11 

Boston, Mass., Board of Health 6, 67 

Boston, Mass., Master Plumbers' Assn... 

6, 7, 67 

Bowditch, Earnest W 5, 6, 9, 67 

Brown, Glenn 9, 67 

Bridgeport, Conn 16, 67 

Chandler, Prof. Chas. F 10, 67 

Chicago, 111 11, 67 

Cleveland, Ohio 11, 12 

Davenport, la 11, 12, 67 

Elizabeth, N. J 11 

Ehnira, N. Y 11, 12, 13,67 

Gerhard, Dr. Wm. Paul 3, 4, 5 

Hellyer, S. S 4, 5, 9, 67 

Holyoke, Mass 11, 14, 67, 70 

International Correspondence School 

11, 13, 67 

Luff, H. J 67 

Mass. Institute of Technology 8, 67 

National Board of Health 3, 4, 67 * 

Newark, N. J 11 

New York City Board of Standards & 

Appeals at 30 City Hall Place 

22, 23, 25, 26, 70, 72 

At Hallenbeck Bldg 26-36, 70, 71 

New York City Dept. of Health 10 

New York City, 366 West Broadway, 

General Description 13, 35, 36 

4" Stack 36-49, 71 

3" Stack 49-52, 64-66, 72, 73 

Oakland, Cal 11 

Philbrick, Edward S 5, 6, 9, 67 

Portland, Ore 11 

Putnam, J. Pickering 6, 7, 8, 9, 67 

Rice, L. Frederick 6 

Richmond, Va 11, 67 

Rochester, N. Y. . . .11, 13, 14, 15, 16, 60, 67 
San Antonio, Tex 11 



PLUMBING FIXTURE TRAPS 



83 



Traps, Tests of (continued) 

Severity of Tests 45, 46, $7 

Springfield, Mass 11, 15, 16, 67, 70 

Thomson, T. N .11, 13, 67 

U. S. Housing Corp 16, 67 

U. S. Navy Dept 9, 67 

Waring, Geo. F 3, 4, 5, 9, 67 

Washington, D. C/ 11, 12, 67 

Wilkes Barre, Pa 13, 67 

Worcester, Mass 11 

U. S. HOUSING Corp 2, 16, 67 

U. S. Housing Corp. Trap 

39,41-43,47-50, 52,62, 67 

U. S. Navy Dept 9, 10, 67 

Utica, N. Y 18 

VALVE Traps 1-4 

Venting, Patents on 2, 3 

Vented V2 S Traps 1-3, 5, 54-63 



WARING, Col. Geo. E 2-5, 66, 67, 68 

Washington, D. C 12, 18, 19, 21, 22, 67, 68 

Waterbury, Conn. 18 

Waterloo, la 18 

Webster, Albert L 13, 16 

West Hoboken, N. J 17 

Wheeling, W. Va 17 

Wichita, Kan 18 

Wilkes Barre, Pa 13, 17, 67, 68 

Williams, F. H 1 

Wilmington, Del 17 

Wolverine Trap 18 

Woonsocket, R. I . . 13 

Worcester, Mass 18, 67 

YONKERS, N. Y 17 

Young, A. W 19 

Young, Jas. H 2 

Youngstown, Ohio 17 

York, Pa 17 



